DEFRA 2026 Emission Factors — Verified Reference Dataset
Cell-by-cell reconciled UK DEFRA 2026 emission factors. Every value below traces to a specific row in the DEFRA 2026 source workbook (UK Government GHG Conversion Factors, DESNZ, June 2026) and is the same value used in every calculator on this platform.
- Stationary fuels (Scope 1) — 18 combustion factors across liquid, gaseous, and solid fuels
- WTT upstream (Scope 3 Cat 3a) — 5 well-to-tank factors paired with their combustion counterparts
- UK grid electricity (Scope 2) — Great Britain location-based factor, DEFRA 2026
Transport, business travel, freight, waste, water, and refrigerants will follow as MasterBrain coverage expands. We don’t publish factors we haven’t reconciled to source.
DEFRA 2026 uses IPCC AR5 GWP-100 values (CH₄ = 28, N₂O = 265). Stated on the DEFRA 2026 workbook Introduction tab. Every CO₂e factor below therefore carries the AR5 basis. If your reporting framework requires AR6, see our AR6 GWP dataset and the gas-by-gas component values stored alongside each MasterBrain entry. Do not apply additional GWP on top of these factors — it is already embedded.
Stationary Combustion Fuels (Scope 1)
Direct combustion factors for fuels burned in boilers, furnaces, generators, and other fixed plant under operational control. These are tank-to-wheel factors — the Scope 1 component only. Upstream extraction and supply emissions appear separately in the well-to-tank table below as Scope 3 Category 3a. CV basis is GCV (Gross Calorific Value, also called HHV) throughout, matching DEFRA’s internal convention.
Liquid fuels (kg CO₂e per litre)
| Fuel | Factor | Notes |
|---|---|---|
| Diesel (UK pump, B7 blend) | 2.58354 | Standard road and stationary diesel (7% FAME by volume). |
| Diesel HVO (hydrotreated vegetable oil) | 0.03558 | Renewable diesel. Scope 1 covers trace CH₄ and N₂O only; biogenic CO₂ reported out of Scope. |
| Gas oil (red diesel) | 2.75541 | Pure fossil — no biofuel blend. Generators, agricultural equipment. |
| Petrol (UK pump, average biofuel blend) | 2.075 | Standard UK pump petrol (E10 since 2021). |
| LPG (liquefied petroleum gas) | 1.55713 | Standard UK LPG blend (commercial propane / butane mix). |
| Aviation turbine fuel (Jet A-1) | 2.54269 | Scope 1 only — for company-owned aircraft. Business travel flights are Scope 3 Cat 6 (not yet in MasterBrain). |
| Burning oil (kerosene heating oil) | 2.54016 | Domestic and rural heating kerosene (28-second oil). Distinct from gas oil. |
| Fuel oil (heavy residual) | 3.17492 | Industrial steam, marine bunker, large-scale heat. |
| Marine gas oil (MGO) | 2.77139 | Marine distillate. Port-side stationary boilers and marine auxiliary engines. |
| Biodiesel ME / FAME B100 (generic) | 0.16751 | Pure (100%) FAME biodiesel. Scope 1 covers trace CH₄ and N₂O; biogenic CO₂ (~2.39 kg/L) out of Scope. |
Gaseous fuels
| Fuel | Factor | Unit | Notes |
|---|---|---|---|
| Natural gas (energy basis) | 0.18231 | kg CO₂e / kWh (GCV) | Use when UK gas bills meter in kWh — the modern standard for domestic and most commercial sites. |
| Natural gas (volume basis) | 2.02633 | kg CO₂e / m³ | Volume at 15°C, 1 atm. Use for industrial volume meters. Includes methane slip. |
| CNG (compressed natural gas) | 0.43885 | kg CO₂e / litre | Vehicle and stationary use. Volume measured at storage pressure. |
| LNG (liquefied natural gas) | 1.14791 | kg CO₂e / litre | Cryogenic liquid. Typical use: marine and heavy transport. |
Solid fuels
| Fuel | Factor | Unit | Notes |
|---|---|---|---|
| Coal — industrial / steam | 2415.03994 | kg CO₂e / tonne | Industrial steam generation, process heat. |
| Coal — domestic | 2904.95234 | kg CO₂e / tonne | Domestic heating coal. Highest CH₄ component due to inefficient open-fire combustion. |
| Coking coal (metallurgical) | 3164.65002 | kg CO₂e / tonne | Metallurgical coking coal — steel-making feedstock. |
| Biomass — wood pellets | 0.01193 | kg CO₂e / kWh | Combustion CH₄ + N₂O only. Biogenic CO₂ excluded per GHG Protocol; report as supplementary. |
Need to apply these factors? Open the Scope 1 Stationary Combustion Calculator →
Well-to-Tank Upstream Factors (Scope 3 Category 3a)
Upstream emissions from fuel extraction, refining, and supply to the point of combustion. Required by GHG Protocol Scope 3 Category 3a (fuel- and energy-related activities not in Scope 1 or 2). Apply alongside the Scope 1 combustion factor above — the two together represent total well-to-wheel emissions.
| Fuel | WTT factor | Unit | Combustion (S1) for reference |
|---|---|---|---|
| Diesel | 0.61101 | kg CO₂e / litre | 2.58354 |
| Petrol | 0.58094 | kg CO₂e / litre | 2.075 |
| Natural gas (energy basis) | 0.03021 | kg CO₂e / kWh (GCV) | 0.18231 |
| Natural gas (volume basis) | 0.3366 | kg CO₂e / m³ | 2.02633 |
| LPG | 0.18551 | kg CO₂e / litre | 1.55713 |
MasterBrain v2026.136 also holds WTT factors for gas oil, fuel oil, aviation fuel, burning oil, marine gas oil, biodiesel (with feedstock-specific differentiation for used cooking oil, tallow, and generic FAME), HVO, CNG, LNG, and biomass wood pellets. Calculator pages surface these automatically when the corresponding combustion fuel is selected.
For background on Scope 3 Category 3a definitions, see the GHG Protocol Corporate Standard reference →
UK Grid Electricity (Scope 2)
Location-based grid intensity factor for purchased electricity in Great Britain. This is the value required for location-based Scope 2 reporting under the GHG Protocol Corporate Standard. Market-based Scope 2 reporting (where RECs, REGOs, or PPAs are held) requires supplier-specific or instrument-specific factors that DEFRA does not publish.
| Region | Factor | Unit | Notes |
|---|---|---|---|
| UK (Great Britain) | 0.131 | kg CO₂e / kWh | Location-based, generation only. Excludes WTT and T&D losses (those are separate Scope 3 Cat 3 factors). |
DEFRA only publishes a UK grid factor. For all other countries use Ember electricity intensity data — currently sourced from Ember Yearly Electricity 2025 in MasterBrain. Examples (kg/kWh — Ember 2025 values are CO₂, the US EPA eGRID 2023 value is CO₂e): Singapore 0.497, Germany 0.330, France 0.041, Australia 0.525, US 0.350, India 0.670. Never apply the UK grid factor to non-UK electricity — for coal-heavy grids it understates Scope 2 by more than half.
DEFRA 2025 → 2026 Change Log
What changed when this dataset rolled from the DEFRA 2025 edition to DEFRA 2026 (published June 2026, reconciled to MasterBrain v2026.136). Factors not listed here were carried forward unchanged by DEFRA at the same published value. The GWP basis is unchanged — DEFRA 2026 still uses IPCC AR5 GWP-100 (CH₄ = 28, N₂O = 265). The frozen DEFRA 2025 edition stays permanently citable at its own version DOI (see Cite this dataset below).
| Factor | DEFRA 2025 | DEFRA 2026 | Change |
|---|---|---|---|
| UK grid electricity (Scope 2) | 0.177 | 0.131 | −26%. Continued fall in gas generation and a higher renewable share in the 2025 GB generation mix. kg CO₂e/kWh. |
| Diesel (average biofuel blend) | 2.57082 | 2.58354 | +0.5%. kg CO₂e/litre. |
| Petrol (average biofuel blend) | 2.06916 | 2.075 | +0.3%. kg CO₂e/litre. |
| Natural gas (energy basis) | 0.18296 | 0.18231 | −0.4%. kg CO₂e/kWh (GCV). |
| Natural gas (volume basis) | 2.06672 | 2.02633 | −2.0%. kg CO₂e/m³. |
| CNG (compressed natural gas) | 0.4507 | 0.43885 | −2.6%. kg CO₂e/litre. |
| LNG (liquefied natural gas) | 1.17797 | 1.14791 | −2.6%. kg CO₂e/litre. |
| Coal — industrial / steam | 2,395.28994 | 2,415.03994 | +0.8%. kg CO₂e/tonne. |
| Biomass — wood pellets | 0.0115 | 0.01193 | +3.7%. kg CO₂e/kWh (combustion CH₄ + N₂O; biogenic CO₂ excluded). |
Factors unchanged from DEFRA 2025
All WTT (Scope 3 Cat 3a) upstream factors, and the combustion factors not listed above — HVO, gas oil, LPG, aviation turbine fuel, burning oil, fuel oil, marine gas oil, biodiesel ME, coal (domestic), and coking coal — are unchanged from DEFRA 2025. DEFRA carried them forward at the same published value; every one was nonetheless re-verified cell-by-cell against the DEFRA 2026 source workbook.
GWP basis — unchanged in 2026
DEFRA 2026 continues to use IPCC AR5 GWP-100 (CH₄ = 28, N₂O = 265), the same basis as DEFRA 2025, so no CO₂e factor was re-stated for a GWP-version change this cycle. If your reporting framework requires AR6 (CH₄ = 29.8, N₂O = 273), use the gas-by-gas component values stored alongside each MasterBrain entry — calculator engineering mode applies AR6 automatically; regulatory mode inherits DEFRA’s AR5 basis. Both are disclosed in calculator audit trails.
Track every change to GreenCalculus calculators and methodology pages on the public changelog →
Data access — REST API
This dataset is published as a versioned, machine-readable JSON endpoint — the same canonical factors shown in the tables above, each carrying its GHG-Protocol scope, gas, GWP basis, and per-row source citation. It is a live projection over the GreenCalculus MasterBrain (the single source of truth the calculators read), versioned by data release and citable for DOI deposit.
/wp-json/greencalculus/v1/defra-factors — every UK DEFRA 2026 fuel combustion factor on this page (Open Government Licence v3.0). The response includes a sources block with full citation and licence, and an X-GC-Version header so consumers can detect updates without diffing.
Cite this dataset (GreenCalculus compilation). Each edition is permanently archived on Zenodo. Cite the always-latest concept DOI — it resolves to the current edition — or a specific edition’s immutable version DOI:
Say, Jeremiah (2026). UK DEFRA fuel combustion emission factors (machine-readable). GreenCalculus. Zenodo. https://doi.org/10.5281/zenodo.20612999
GreenCalculus dataset — concept DOI (always resolves to the latest edition)
Editions. Each edition keeps its own immutable version DOI under the concept DOI above. Current — DEFRA 2026 (v2026.4): 10.5281/zenodo.20754776. Previous — DEFRA 2025 (v2025.69): 10.5281/zenodo.20613000.
Provenance
Every MasterBrain v2026.136 entry carries a _provenance block recording the exact source workbook, tab name, row label, and row number it was reconciled against. This metadata is exposed to calculator audit trails and JSON exports, allowing any practitioner or verifier to trace any factor displayed on this site back to the originating DEFRA cell. Example for the diesel entry:
'_provenance' => [
'source' => 'UK Government GHG Conversion Factors 2026, DESNZ, June 2026',
'workbook' => 'ghg-conversion-factors-2026-full-set.xlsx',
'tab' => 'Fuels',
'row_label' => 'Diesel (average biofuel blend)',
'row_number' => 72,
],For audit purposes, the canonical source workbook can be downloaded from the UK government at gov.uk/government/collections/government-conversion-factors-for-company-reporting. Licensed under Open Government Licence v3.0.
Related
Frequently Asked Questions
On an energy basis (the standard for UK gas bills) the DEFRA 2026 factor is 0.18231 kg CO₂e per kWh GCV. On a volume basis (industrial meters) it is 2.02633 kg CO₂e per m³ at 15°C and 1 atm. Both factors embed IPCC AR5 GWP-100 values (CH₄ = 28, N₂O = 265) — the basis DEFRA uses internally in 2026. Don’t apply additional GWP on top; it is already included. Both factors include the small CH₄ component from methane slip during combustion.
The UK (Great Britain) location-based grid factor for DEFRA 2026 is 0.131 kg CO₂e per kWh, a 26% reduction from 0.177 in DEFRA 2025. The drop reflects a continued decline in natural gas generation and a higher renewable share in the 2025 generation mix. This is a location-based factor for standard Scope 2 reporting. Market-based Scope 2 reporting (RECs, REGOs, or PPAs) requires supplier-specific or instrument-specific factors that DEFRA does not publish. For non-UK electricity use Ember country-specific factors.
DEFRA 2026 uses IPCC AR5 GWP-100 values (CH₄ = 28, N₂O = 265). This is stated explicitly on the DEFRA 2026 workbook Introduction tab and is unchanged from DEFRA 2025. We re-verified the basis during the MasterBrain v2026.136 reconciliation in June 2026. If your reporting framework requires AR6 (CH₄ = 29.8, N₂O = 273), you have two options: use the gas-by-gas component values stored in MasterBrain alongside each fuel and apply AR6 yourself (calculator engineering mode does this automatically), or accept the AR5 basis as inherited from DEFRA’s published values (calculator regulatory mode). Both bases are disclosed in calculator audit trails.
HVO (hydrotreated vegetable oil) is a renewable diesel made from biological feedstocks. Under the GHG Protocol, the CO₂ released during combustion is biogenic — it returns carbon that the source biomass recently absorbed from the atmosphere, so it is excluded from Scope 1 CO₂e and reported as a supplementary biogenic figure instead. The 0.03558 kg CO₂e/litre value covers only the trace CH₄ and N₂O components of HVO combustion, which are not biogenic. This treatment is consistent with DEFRA 2026 and with IPCC inventory guidance for sustainable biofuels. Note that HVO’s well-to-tank (Scope 3 Cat 3a) factor accounts for the fossil energy used in feedstock production and refining and is separately material — see the WTT table above.
For fuel combustion (diesel, natural gas, petrol, LPG, etc.) — yes, fuel chemistry is largely consistent globally and DEFRA combustion factors are widely accepted by CDP and CSRD reviewers as a defensible default outside the UK. For UK grid electricity (0.131 kg CO₂e/kWh) — no. This reflects the UK generation mix only. For a Singapore office the correct factor is 0.497 kg CO₂/kWh (Ember 2025); for Germany it is 0.330; for France 0.041. Applying the UK grid factor to non-UK electricity can understate Scope 2 by more than half on coal-heavy grids. For waste, water, and refrigerant factors, use local national data where available — UK figures reflect UK-specific infrastructure that doesn’t transfer.