Scope 3 Cat 4 Last-Mile Delivery Calculator (Van / Electric / DEFRA)
Compute upstream last-mile delivery emissions for GHG Protocol Scope 3 Category 4 — per vehicle-kilometre for diesel, petrol, and electric vans and rigid trucks on DEFRA 2026 factors, with an optional GLEC tonne-km basis for shared and consolidated loads.
Two activity bases, picked per leg. Last-mile delivery is the one Category 4 mode that is natively measured per vehicle-kilometre rather than per tonne-kilometre — a delivery round visits many drops with a part-full vehicle, so the van-km is the activity that scales, not the tonnage. The calculator’s per-leg Method dropdown offers four bases: DEFRA vehicle-km for diesel and petrol vans and rigid trucks (the default), an electric-van charging-based factor for BEV and PHEV vehicles, a GLEC tonne-km basis for shared or consolidated loads (which reveals a cargo-mass field), and a zero-tailpipe option for cargo-bike or on-foot delivery.
Per-km formula.
Delivery emissions (kg CO₂e) = Distance (vehicle-km) × per-km factor (kg CO₂e per vehicle-km)
Tonne-km formula (GLEC shared-load basis).
Delivery emissions (kg CO₂e) = Mass (tonnes) × Distance (km) × WTW intensity (kg CO₂e per tonne-km)
The two bases combine at the emissions level, never by adding activity units. Each leg computes its own emissions in its native unit — vehicle-km legs in vehicle-km, the GLEC leg in tonne-km — and the portfolio total sums kilograms of CO₂e only. The calculator never adds a vehicle-km to a tonne-km, so the unit-mixing error that the dual basis might invite is impossible by construction.
Vehicle, fuel, laden state. The DEFRA per-km factors segment by vehicle type (van by DEFRA class, or rigid HGV by size class) and fuel (diesel, petrol, or electric via the charging factor). Rigid-truck factors additionally segment by laden percentage — empty, half, full, or the weighted average — because a delivery vehicle’s per-km emissions rise with the load it carries. Pick the vehicle and fuel that match the leg; where the laden state is unknown, the average band is the defensible default.
Electric is grid-based, not zero. The electric-van factor is a charging-based figure — the emissions of generating the electricity drawn to charge the battery, on the destination-country grid. Nothing burns at the tailpipe, so the vehicle’s direct combustion is zero, but the well-to-wheel footprint is real and sits entirely upstream in the grid.
Mixed GWP vintages are flagged, not silently summed. The DEFRA van and electric factors are on an IPCC AR5 GWP-100 basis; the optional GLEC tonne-km factors are on AR6. If a portfolio combines the two, the calculator surfaces a warning rather than reweighting them into a single vintage — see the data-sources section for how to disclose a mixed-basis total.
Category boundary. This calculator covers upstream last-mile transport and distribution (GHG Protocol Scope 3 Category 4) — the final delivery leg to the customer or drop point. The same factors apply to downstream distribution under Category 9. Trunk freight (road, sea, air, rail) and refrigerated cold-chain delivery use their own factor sets and are out of scope here.
DEFRA 2026 (vehicle-km, TTW + WTT companion · AR5) + GLEC Framework v3.2 (tonne-km, WTW · AR6) + Ember grid for electric. Reads MasterBrain V3 live.
Add a fleet row above and click Calculate
Results show total tCO₂e and kg CO₂e per parcel, a well-to-tank / tank-to-wheel split, per-row breakdown, data-quality scoring, a fleet-electrification scenario, audit trail, and export.
Results are indicative and for organisational greenhouse-gas accounting under the GHG Protocol Scope 3 Standard (Category 4, last-mile leg). DEFRA 2026 delivery-vehicle factors are tank-to-wheel with a separately-published well-to-tank companion (AR5 GWP-100); UK electric-van factors are DEFRA’s published location-based values, while other grids are modelled from energy use × grid intensity. GLEC Framework v3.2 intensities are well-to-wheel (AR6 GWP-100). Per-parcel intensity bands are indicative industry ranges, not a regulatory threshold. Verify the boundary, allocation, distance and parcel basis against your carrier data before external reporting; for assured disclosure obtain third-party verification under ISO 14064-3.
Last-mile delivery is the most visible and most awkward leg of a supply chain — the van that pulls up outside the door, the round that visits forty drops on a part-full load, the courier on an e-bike. It is also where freight emissions accounting stops behaving like every other mode.
Trunk freight is priced per tonne-kilometre; last-mile is priced per vehicle-kilometre — and getting that distinction right is the difference between a defensible figure and a category error.
Last-mile delivery emissions equal distance (vehicle-km) × the DEFRA per-km factor for the vehicle and fuel. An electric delivery van is far lower-carbon than diesel but not zero — the UK average BEV van runs at about 0.0644 kg CO₂e per km well-to-wheel, all from the grid.
What last-mile delivery covers in Scope 3 Category 4
GHG Protocol Scope 3 Category 4 — upstream transportation and distribution — covers the third-party logistics a reporting company pays for to bring goods in. Last mile is the final leg of that chain: the parcel van, the home-delivery round, the urban rigid truck, the cargo bike. It is short-distance, high-frequency, part-laden, and increasingly electrified — a different operational shape from the long-haul trunk legs that move goods between hubs.
Category 4 vs Category 9 — same factors, different direction
The line between Category 4 and Category 9 is the direction of the goods flow, not the arithmetic. Category 4 is upstream — delivery the reporting company pays for, bringing goods in or moving them between its own sites. Category 9 is downstream — delivery of sold products to the end customer after they leave the company’s control. The per-km and per-tonne-km factors are identical across both; only the Scope 3 category line the result is booked to changes. A retailer’s own home-delivery fleet delivering to shoppers is Category 9 downstream; the same retailer paying a courier to bring stock into a store is Category 4 upstream.
Mode boundary — what’s in, what’s elsewhere
| Covered in this calculator | Out of scope — separate mode or calculator |
|---|---|
| Diesel and petrol delivery vans by DEFRA class, per vehicle-km | Long-haul road freight — heavy goods vehicles by region, class, and load: see the Road Freight Calculator |
| Electric (BEV) and plug-in hybrid (PHEV) delivery vans, charging-based per km | Sea freight — per tonne-km and per TEU-km: see the Sea Freight Calculator |
| Urban rigid trucks by size class and laden percentage, per vehicle-km | Air freight — bellyhold and freighter by haul length: see the Air Freight Calculator |
| The GLEC tonne-km basis for shared and consolidated last-mile loads | Rail freight — per tonne-km by region, traction, and commodity (calculator live; slug pending in the link index) |
| Cargo-bike and on-foot delivery (zero-tailpipe), and both the Cat 4 and Cat 9 framing of a delivery leg | Cold-chain delivery — refrigerated vans add reefer-energy and refrigerant-leakage components (separate calculator, in development) |
Last mile is the freight leg where electrification is furthest advanced and most measurable. A battery-electric delivery van on the UK grid runs at roughly 0.0644 kg CO₂e per km well-to-wheel — a fraction of its diesel equivalent — but that figure is not zero: it is the upstream grid emissions of charging the battery. The calculator reports it as a real, grid-based well-to-wheel number, which is exactly what an assurer expects to see.
Why last-mile is measured per vehicle-km, not per tonne-km
Every other Category 4 mode prices emissions per tonne-kilometre: a tonne of cargo carried one kilometre. That works for a bulk train or a container ship, where the vehicle is loaded close to capacity and the tonnage is what scales. Last mile breaks the assumption. A parcel van on a delivery round is rarely full, visits dozens of drops, and the thing that drives its fuel burn is the distance it covers, not the mass it happens to be carrying at any moment. So the defining basis for last mile is the vehicle-kilometre — the distance the delivery vehicle travels, regardless of how laden it is.
Two bases, and when each applies
The calculator exposes both. The per-vehicle-km basis is the default and the right choice for a dedicated delivery vehicle whose route you can measure. The per-tonne-km basis — drawn from the GLEC road set — is the right choice when your goods share a consolidated load with other shippers’ freight and you are allocated a tonnage share rather than a whole vehicle. Choosing the GLEC tonne-km method reveals a cargo-mass field; choosing any of the vehicle-km methods asks only for distance.
| Vehicle-km basis (default) | Tonne-km basis (GLEC shared load) | |
|---|---|---|
| Activity unit | Vehicle-kilometre | Tonne-kilometre (mass × distance) |
| Input asked for | Distance only | Cargo mass and distance |
| Right when | You operate or pay for a whole delivery vehicle on a measurable route | Your goods ride a consolidated load and you hold a tonnage allocation |
| Factor source | DEFRA 2026 delivery-vehicle factors (AR5) | GLEC Framework road set (AR6) |
| Powertrain handling | Diesel, petrol, and a separate charging-based electric factor | Combined WTW intensity per tonne-km |
The dual-basis trap — and why this calculator avoids it
Mixing the two bases is the classic last-mile reporting error: adding a fleet’s vehicle-kilometres to an allocated tonne-kilometre figure produces a number with no coherent unit. The calculator makes that error structurally impossible. Each leg is computed in its own native unit and only the resulting kilograms of CO₂e are summed into the portfolio total — the tool never adds a vehicle-km to a tonne-km. You can run a mixed portfolio of per-km van legs and a GLEC tonne-km consolidated leg in one calculation, and the total is a clean emissions sum even though the activity units differ.
Default to the vehicle-km basis unless you genuinely hold a tonnage allocation on a shared load. For a dedicated delivery round — your van, your route — the vehicle-km factor is both more accurate and easier to defend, because the activity data is an odometer reading rather than an estimated mass share. Reserve the GLEC tonne-km basis for the consolidated-freight case it is built for.
Vehicle type, fuel, and the diesel-to-electric decision
On the vehicle-km basis the factor is set by two choices: what kind of vehicle runs the leg, and what powers it. The vehicle axis runs from a small parcel van up to an urban rigid truck; the fuel axis is diesel, petrol, or electric — and electric is handled differently from the two combustion fuels.
Why the electric factor is computed differently
A diesel or petrol van’s emissions are tailpipe combustion plus the upstream fuel supply — a mobile-combustion factor. An electric van burns nothing at the tailpipe, so its factor is a charging-based figure: the emissions of generating the electricity drawn to charge the battery, on the destination-country grid. That is why the calculator surfaces electric vehicles through a distinct charging factor rather than a fuel one. The UK-average battery-electric van charging factor is about 0.0426 kg CO₂e per km; a battery-electric car, lighter and more efficient, is lower still at roughly 0.02686 kg CO₂e per km on the same grid.
Electric factors: DEFRA 2026 charging-based, UK grid, AR5 GWP-100, kg CO₂e per km. The diesel-van bar is the live DEFRA delivery-van factor surfaced by the calculator — substantially higher than the electric rows; the exact per-km value is read from the Master Brain at run time rather than reproduced here.
The electric figure is grid-coupled
Because the electric factor is the grid behind the charge, it tracks the destination country’s electricity emission factor. On a low-carbon grid an electric van runs cleaner than the UK figure; on a coal-heavy grid it runs higher. The calculator’s charging factors are keyed by destination country, so select the grid where the vehicle actually charges rather than borrowing the UK default for a non-UK fleet.
An electric delivery van is not zero-carbon. Its tailpipe emissions are zero, but its well-to-wheel footprint — the grid emissions of charging — is real and is what the calculator reports. Booking electric last-mile as zero is a common assurance finding. Confirm the figure used is the charging-based well-to-wheel factor, and that the grid selected matches where the vehicle charges.
Why laden percentage changes the truck factor
For rigid trucks — the larger end of the last-mile fleet — the DEFRA factor segments not just by size class but by how laden the vehicle is. A truck carrying a full load burns more fuel per kilometre than the same truck running empty, so DEFRA publishes the factor at four laden states: empty (0%), half (50%), full (100%), and a weighted average that reflects a typical duty cycle including return legs.
The empty-running figure matters more than it looks: a delivery round that goes out laden and returns empty spends a large share of its kilometres carrying nothing, and an inventory that prices every kilometre at the full-laden factor will overstate the round. The weighted-average band exists precisely to capture that out-and-back duty cycle in a single factor.
DEFRA 2026, diesel, 0% laden, kg CO₂e per vehicle-km. Empty-running factors shown for comparison across HGV groupings; the 50%, 100%, and weighted-average laden bands are selectable per leg in the calculator. Vans are not laden-segmented — a single per-km factor per van class and fuel.
Where the laden state of a leg is genuinely unknown, the weighted-average band is the honest default — it already accounts for a realistic mix of laden and empty running. Pricing an out-and-back round at the full-laden factor overstates it; pricing it at empty understates it. Match the laden band to the duty cycle where you know it, and use the average where you don’t.
How the calculation works — two activity bases
Each leg reduces to one multiplication, run per leg and summed into the emissions total. Which multiplication depends on the basis you select for that leg.
Per vehicle-km: kg CO₂e = Distance (vehicle-km) × per-km factor
Per tonne-km: kg CO₂e = Mass (tonnes) × Distance (km) × WTW intensity
Vehicle-km legs
Enter the distance the delivery vehicle travels and select vehicle, fuel, and (for trucks) laden band. The calculator multiplies distance by the per-km factor. This is the default and the right basis for a dedicated delivery vehicle on a measurable route.
Tonne-km legs
Select the GLEC shared-load method and a cargo-mass field appears. Enter mass and distance; the calculator multiplies through the GLEC WTW intensity. Use this only when your goods ride a consolidated load and you hold a tonnage allocation.
Zero-tailpipe legs
Cargo-bike and on-foot delivery contribute zero tailpipe emissions and are entered as a zero-tailpipe method. They appear in the leg breakdown for completeness and add nothing to the total.
Well-to-wheel, and the electric mirror image
Every headline factor is a well-to-wheel figure — the full upstream-energy-plus-traction footprint. For diesel and petrol that is dominated by tailpipe combustion, with the upstream fuel-supply share added on; see the well-to-tank definition for the upstream boundary. For electric it is the reverse: tailpipe is zero and the entire footprint is upstream grid generation. Reporting traction alone would understate diesel and zero out electric — which is why the well-to-wheel total is the figure that feeds the inventory.
Whose emissions? Scope 1, Scope 2, and Scope 3 Cat 4
Last mile is unusually easy to mis-scope because the same physical delivery lands in different scopes depending on who is reporting and how the vehicle is powered. The activity is identical; the boundary is not.
| Who is reporting | Diesel / petrol delivery | Electric delivery |
|---|---|---|
| The delivery operator (owns the vehicle) | Scope 1 — mobile combustion of the fuel | Scope 2 — purchased electricity for charging |
| The shipper (pays for the delivery) | Scope 3 Category 4 — upstream transport | Scope 3 Category 4 — upstream transport |
For the operator running its own fleet, a diesel van is mobile combustion in Scope 1 and an electric van is purchased electricity in Scope 2 — two different scopes for the same delivery service, which is why the electric factor is a charging (Scope 2) figure rather than a fuel one. For the shipper buying the delivery, both land in Scope 3 Category 4 regardless of powertrain — it is purchased transport either way. This calculator is built for the shipper’s Category 4 view, but the per-km factors are the same numbers an operator would book to Scope 1 or Scope 2; see the GHG Protocol Scope 2 Guidance for the electricity-accounting boundary.
Do not double-count across scopes. If you are the operator booking electric-van charging to Scope 2, the same kilometres must not also appear in your Scope 3 Category 4. The Category 4 framing is for the party that buys the transport, not the party that operates it. Confirm which side of the transaction you are on before selecting the category line.
Where last-mile sits — van vs rigid vs the trunk modes
Per vehicle-km, a delivery van and a rigid truck are not directly comparable to the trunk modes, which are priced per tonne-km — the units differ. Within the last-mile fleet, though, the ranking is clear: an electric van is the lowest-carbon powered option, a diesel van sits well above it, and a rigid truck higher still per kilometre because it is a larger, heavier vehicle. The cleanest cross-mode comparison comes through the GLEC tonne-km basis, where a consolidated last-mile load can be set against a trunk leg on the same unit.
The practical reading for a decarbonisation plan: electrifying the van fleet is the single largest per-km lever in last mile, and consolidating part-full delivery rounds — fewer vehicle-kilometres for the same drops — is the second. Both show up directly in the calculator: electrification by switching the fuel basis, consolidation by reducing the vehicle-km entered. For the long-haul legs that feed the last mile, the road, sea, and air freight calculators carry the tonne-km factor sets for those modes.
Worked example — a diesel and an electric round
This example contrasts the same delivery operation run on diesel versus battery-electric vans, to quantify the electrification lever. The electric leg is computed on the documented UK-average BEV-van charging factor; the diesel comparison uses the calculator’s live DEFRA delivery-van factor. Both are vehicle-km legs on the per-km basis. Figures are DEFRA 2026, AR5 GWP-100.
Leg — electric van round, UK grid
| Vehicle / fuel / grid | Distance | Per-km factor | Emissions (kg CO₂e) |
|---|---|---|---|
| BEV van · UK grid · charging-based | 138,300 km | 0.06442 kg/km | 8,909 |
Emissions = 138,300 × 0.06442 = 8,909 kg CO₂e (8.909 tCO₂e); the per-km figure is charging (0.0426) plus grid T&D losses (0.00423) plus upstream fuel (0.01759). The entire footprint is upstream UK-grid generation — tailpipe combustion is zero. This matches the calculator’s engine-verified BEV-van total for the example fleet activity.
Same operation on diesel vans
Run on the calculator’s live DEFRA diesel delivery-van factor over the same fleet distance, the diesel equivalent of this operation totals about 44.04 tCO₂e (0.25716 tank-to-wheel + 0.06128 well-to-tank = 0.31844 kg CO₂e per km). The contrast is the abatement available from electrifying the fleet on the current UK grid.
The electric round is roughly 80% below the diesel one on today’s UK grid, and that gap widens as the grid decarbonises — the electric figure tracks the grid, so it falls each year the generation mix cleans up. The diesel figure does not. That divergence is the business case for electrifying a last-mile fleet, and reporting both bases for the same operation makes it explicit.
Report the diesel and electric figures as a pair for any round you are considering electrifying. The difference is the abatement you can attribute to the switch, and stating both — with the electric figure’s grid basis named — turns the calculator into a fleet-electrification business case rather than a single number.
Data quality and the default hierarchy
The reporting expectation is to use the most specific data available and climb toward measured energy where the emissions are material. For last mile, the largest accuracy gains usually come from getting the vehicle, fuel, and laden state right, and from measuring actual route distance rather than estimating it.
| Tier | Input shape | When it applies |
|---|---|---|
| Primary energy | Measured diesel litres or charging kWh for the fleet, converted via energy factors | Where the operator shares actual fuel or electricity consumption — the most precise basis |
| Primary activity + modelled factor | Measured route distance (odometer / telematics) with the DEFRA per-km factor for the vehicle and fuel | The default for most reporting — actual distance, modelled factor. This calculator’s primary mode. |
| Allocated tonne-km | Cargo-mass share and distance with the GLEC shared-load intensity | Where goods ride a consolidated load and only a tonnage allocation is known |
| Fleet-average default | Estimated distance with the weighted-average laden band or the all-vehicle average factor | The fallback where the specific vehicle, fuel, or laden state is not known |
The honest disclosure is the mix. A last-mile inventory that uses measured route distance and the correct vehicle-and-fuel factor where it can, and the fleet-average default only where it must, is well constructed. Claiming vehicle-specific precision across an entire fleet that is mostly modelled on a single average factor is the disclosure failure, not the use of defaults.
Audit checklist — what gets flagged in last-mile assurance
Last-mile assurance traces each leg from activity data to the rolled-up total. The findings below are the issues raised most often on a last-mile inventory specifically.
01 — Electric delivery booked as zero
Treating electric vans as zero-carbon because nothing burns at the tailpipe. The charging emissions are real and sit in the grid. Confirm the factor is the charging-based well-to-wheel figure, on the grid where the vehicle actually charges.
02 — Vehicle-km and tonne-km mixed as activity
Adding a fleet’s vehicle-kilometres to an allocated tonne-kilometre figure. The two are incompatible units. Keep each leg in its native basis and combine only at the emissions level — which is how the calculator handles it by construction.
03 — Scope boundary error
The operator double-counting electric charging in both Scope 2 and Scope 3 Category 4, or a shipper booking purchased delivery to Scope 1. Confirm which side of the transaction you are on; Category 4 is for the party that buys the transport.
04 — Full-laden factor on an out-and-back round
Pricing every kilometre of a delivery round at the full-laden truck factor, ignoring empty return running. Use the laden band that matches the duty cycle, or the weighted average where the cycle is unknown.
05 — Wrong grid for the electric factor
Applying the UK-average charging factor to a fleet that charges on a different national grid. The charging factor is grid-keyed; select the destination country where the vehicle charges, not a default.
06 — Estimated distance taken as measured
Using a straight-line or planned distance instead of the actual route distance from telematics or odometer. Delivery rounds cover far more distance than the point-to-point geography suggests; use measured route distance for the leg.
Reporting context — Scope 3, IFRS S2, CSRD
Last-mile emissions feed the same disclosure regimes as the rest of the transport inventory. The framework rows below cover the disclosure surface a typical shipper or retailer navigates.
| Framework | Role for last-mile emissions | Disclosure cadence |
|---|---|---|
| GHG Protocol Scope 3 Standard | The accounting standard. Defines Category 4 (upstream transport & distribution) and Category 9 (downstream) and the activity-data and average-data method options last mile uses. | Same as the institution’s reporting cycle |
| UK DEFRA 2026 factors | The factor source for the per-km delivery-vehicle and electric-van figures. Published annually on an AR5 GWP-100 basis. | Annual factor refresh |
| IFRS S2 (ISSB) | The global disclosure baseline. Requires Scope 3 disclosure including transport categories where material, with the calculation methodology disclosed. | Annual, aligned with financial statements |
| CSRD ESRS E1 (EU) | The EU sustainability-reporting mandate. ESRS E1 requires Scope 3 disclosure for in-scope companies, with transport and distribution assessed for materiality. | Annual sustainability statement |
Data sources, mixed-basis reconciliation, and GWP basis
Per-km factors — source and structure
The vehicle-km factors are drawn from the DEFRA 2026 conversion factors, retrieved for the MasterBrain factor set. Diesel and petrol delivery vehicles — vans by DEFRA class and rigid trucks by size class and laden percentage — are mobile-combustion factors. Electric vans (BEV and PHEV) are charging-based factors keyed by destination-country grid. The optional shared-load basis uses the GLEC Framework road set on a per-tonne-km footing.
Mixed GWP vintages — and how the tool handles them
This is a genuinely mixed-basis calculator, and that is a defensibility feature rather than a flaw to hide. The DEFRA van and electric factors are on an IPCC AR5 GWP-100 basis — the convention DEFRA publishes on. The optional GLEC tonne-km factors are on AR6. A portfolio built entirely from the DEFRA per-km factors is cleanly AR5; one that adds a GLEC shared-load leg combines AR5 and AR6 figures.
The calculator does not silently sum across vintages. When a portfolio mixes the two, it surfaces a warning and an insight — that the total blends DEFRA AR5 and GLEC AR6 figures and is not a single-vintage number — and it never reweights one basis into the other. The two are added only at the emissions level, with the mixing disclosed. For disclosure, state which legs are AR5 (DEFRA vans and electric) and which are AR6 (GLEC shared-load tonne-km), and note that the total is a mixed-vintage sum rather than implying a single basis. See the global warming potential definition for the AR5-to-AR6 distinction this rests on.
A clean last-mile inventory built only from the DEFRA per-km factors is single-basis AR5 and needs no reconciliation. The moment a GLEC tonne-km leg is added, the total is mixed AR5/AR6 — and the right move is to disclose that, not to paper over it. The calculator flags the mixing for you; your disclosure should carry the same flag.
The electric factor’s grid basis
The electric-van charging factors embed the destination-country grid mix at the DEFRA publication vintage; they are not recomputed against a user-supplied grid factor. Real-world electric-van intensity tracks the local electricity emission factor, which varies widely and falls year on year as grids decarbonise. For context on how grid factors differ by country, see the grid emission factors reference — background context, not an input the last-mile calculator reads. The full underlying factor tables sit in the DEFRA emission factors reference.
Versioning and update cadence
DEFRA publishes factor refreshes annually and the MasterBrain factor set tracks each publication. The calculator stamps each result with the MasterBrain version against which it was computed, so a leg computed against one factor vintage and the same leg recomputed against a later vintage are distinguishable in restatement work.
What’s next — completing your Category 4 inventory
Last mile is one leg of a chain that usually spans several modes. A complete Category 4 footprint covers the trunk haul as well as the final delivery. The road, sea, and air calculators are live; the remaining modes are on the GreenCalculus build roadmap.
Live
Road Freight
GLEC + DEFRA road set. Tonne-km × WTW intensity by region, class, load, and fuel.
Live
Sea Freight
GLEC sea set. Per-tonne-km for bulk, tanker, and RoRo; per-TEU-km for container.
Live
Air Freight
GLEC air set. Per-tonne-km by aircraft deck and haul length.
Live
Last-Mile Delivery
DEFRA per-km vans and trucks plus a GLEC tonne-km basis, with the diesel/electric scenario. The calculator on this page.
Live
Rail Freight (link pending)
GLEC rail set. Per-tonne-km by region, traction, and commodity. Calculator live; slug pending in the link index.
Live
Cold-chain logistics
Refrigerated delivery adds reefer-energy and refrigerant-leakage components on top of the transport intensity.
Live
GHG Inventory Aggregator
Roll Category 4 together with every other Scope 1, 2 and 3 source into one auditable corporate carbon footprint — the organisation-level inventory this category feeds into.
Separately from the upstream Category 4 modes above, downstream transport — the delivery of sold products after they leave the company’s control — is accounted under Scope 3 Category 9, not Category 4. It uses the same delivery factors but books to a different category line. A dedicated downstream transport calculator is on the roadmap and is not yet published.
Frequently asked questions
A delivery round visits many drops on a part-full vehicle, so the thing that drives its fuel burn is the distance travelled, not the mass carried. That makes the vehicle-kilometre the natural activity unit. The calculator defaults to per-vehicle-km and offers a GLEC per-tonne-km basis only for shared, consolidated loads where you hold a tonnage allocation rather than a whole vehicle.
No. Nothing burns at the tailpipe, so direct combustion is zero, but the well-to-wheel footprint is real and sits entirely in generating the electricity to charge the battery. The UK-average BEV van charging-based factor is about 0.0644 kg CO₂e per km well-to-wheel. Booking electric last-mile as zero is an assurance finding — confirm the figure used is the charging-based well-to-wheel factor.
On the current UK grid an electric van runs roughly 70% below its diesel equivalent per kilometre, and the gap widens each year as the grid decarbonises. The electric figure tracks the grid and falls over time; the diesel figure does not. Reporting both for the same round quantifies the abatement available from electrifying the fleet.
It depends on who reports. For the operator that owns the vehicle, a diesel van is Scope 1 (mobile combustion) and an electric van is Scope 2 (purchased electricity for charging). For the shipper that pays for the delivery, both are Scope 3 Category 4 regardless of powertrain. This calculator is built for the shipper’s Category 4 view. Do not count the same kilometres in two scopes.
Yes, safely. The calculator computes each leg in its own native unit and sums only the resulting kilograms of CO₂e — it never adds a vehicle-km to a tonne-km. So a portfolio of per-km van legs and a GLEC tonne-km consolidated leg produces a clean emissions total even though the activity units differ. The unit-mixing error the dual basis might invite is impossible by construction.
A rigid truck burns more fuel per kilometre carrying a full load than running empty, so DEFRA publishes the factor at empty (0%), half (50%), full (100%), and a weighted average. A delivery round that goes out laden and returns empty spends many kilometres carrying nothing — pricing all of them at the full-laden factor overstates the round. Use the band that matches the duty cycle, or the average where it is unknown.
The grid where the vehicle actually charges. The charging factor is keyed by destination country because an electric van is only as clean as the electricity behind the charge — low-carbon grids run cleaner than the UK figure, coal-heavy grids run higher. Borrowing the UK-average factor for a fleet charging on a different national grid is a common assurance finding.
Yes, and it flags it. The DEFRA per-km van and electric factors are AR5 GWP-100; the optional GLEC tonne-km factors are AR6. A DEFRA-only portfolio is cleanly AR5. Adding a GLEC leg makes the total a mixed AR5/AR6 sum — and the calculator surfaces a warning saying so rather than silently reweighting one basis into the other. Disclose which legs are which vintage.
The actual route distance the delivery vehicle travels — from telematics or odometer — not a straight-line or planned point-to-point distance. Delivery rounds cover far more distance than the geography between origin and destination suggests, so estimated distance understates the emissions. On the tonne-km basis, enter the cargo mass and the routed distance for the consolidated leg.
Both — the factors are identical. The difference is the direction of the goods flow and the category line the result is booked to. Category 4 is upstream delivery the reporting company pays for, bringing goods in. Category 9 is downstream delivery of sold products to the end customer. Use the calculator for either and book the result to the correct category for your reporting boundary.
Methodology notes and limitations
Factor sources and vintage. Calculator implements DEFRA 2026 delivery-vehicle and electric-van charging factors (per vehicle-km, AR5 GWP-100) and, on the optional shared-load basis, the GLEC Framework road set (per tonne-km, AR6 GWP-100). Inventories computed against earlier factor vintages remain auditable against the corresponding MasterBrain version stamp.
Dual activity basis. Per-vehicle-km is the default and primary basis (diesel, petrol, and charging-based electric vans and rigid trucks). A GLEC per-tonne-km basis is selectable per leg for consolidated shared loads and reveals a cargo-mass input. A zero-tailpipe option covers cargo-bike and on-foot delivery. The two bases are combined only at the emissions level — the calculator never sums incompatible activity units.
Mixed GWP vintages are flagged, not reconciled. DEFRA per-km factors are AR5; GLEC tonne-km factors are AR6. A portfolio combining the two is a mixed-vintage sum, and the calculator surfaces a warning and insight to that effect rather than reweighting one basis into the other. A DEFRA-only portfolio is single-basis AR5 and needs no reconciliation. This is the main basis caveat to surface in a mixed-basis disclosure.
Electric factor is grid-based, not zero and not user-recomputed. The electric-van factor is the charging emissions on the destination-country grid at the DEFRA vintage. It is not zero — the footprint is upstream grid generation — and it is not recomputed against a user-supplied grid factor. Select the grid where the vehicle charges; for a markedly cleaner or dirtier grid than the published vintage, treat the figure as indicative and disclose the basis.
Scope boundary. The same delivery falls in different scopes depending on the reporting party: operator diesel = Scope 1, operator electric charging = Scope 2, shipper purchased delivery = Scope 3 Category 4 either way. The calculator is built for the shipper’s Category 4 view. Confirm which side of the transaction you are on and do not double-count across scopes.
Laden bands. Rigid-truck factors segment by laden percentage (0/50/100/weighted average); vans carry a single factor per class and fuel. Match the laden band to the duty cycle where known; the weighted average is the default for an unknown out-and-back cycle.
Activity data taken as entered. The calculator uses the distance, and where applicable the cargo mass, that the user enters; it does not independently verify them. The user is responsible for the activity-data basis and for documenting the vehicle, fuel, grid, and laden selection per leg.
No assurance opinion. Results are estimates and do not constitute an assurance opinion. They should be reviewed by a qualified practitioner before use in IFRS S2 disclosures, CSRD ESRS E1 datapoints, or other regulatory submissions. The full methodological deep-dive — the two activity bases, the scope boundary, the electric grid basis, and the mixed-vintage handling — is published on the paired last-mile delivery methodology page.