IPCC Fuel Combustion Emission Factors — Universal Tier-1 Reference Dataset
When an organisation burns fuel in a country with no published national emission-factor dataset, the IPCC 2006 Guidelines are the universal fallback. They give a Tier-1 default combustion factor for every major fuel — derived from fuel chemistry, not a national fleet average — that is accepted for greenhouse-gas inventories worldwide. A refinery in Singapore, a cement plant in a country without its own factors, or any reporter who needs a defensible, internationally-recognised number reaches for these.
This page publishes the complete set of IPCC universal fuel combustion factors implemented in the GreenCalculus MasterBrain v2026.203 — 37 pre-aggregated CO₂e factors across 16 fuels and four measurement units. All values are on a net calorific value (NCV) basis and use AR5 GWP-100, matching the convention used for national inventory reporting. These factors drive the GreenCalculus Scope 1 Stationary Combustion calculator, and pair with the fuel calorific values dataset.
The IPCC 2006 Tier-1 universal combustion factors, per kWh net calorific value: natural gas 0.202, LPG 0.227, motor gasoline 0.250, jet kerosene 0.258, gas/diesel oil 0.268, coal 0.343–0.366 kg CO2e/kWh. Biogenic fuels carry only their CH4 and N2O in Scope 1.
What these are — and when to use them
These are the IPCC 2006 Tier-1 default combustion factors: single, globally-applicable numbers built from the carbon content and calorific value of each fuel, plus default CH₄ and N₂O emission factors. They exist so that any reporter, anywhere, can produce a defensible fuel-combustion estimate without a national dataset. Each value here is pre-aggregated into a single CO₂e figure using AR5 GWP-100 — the same basis used for national inventory reporting under the Paris Agreement.
Where a country publishes its own emission-factor dataset — the UK’s DEFRA/DESNZ factors, the US EPA factors, and similar — those are more specific to the local fuel mix and take precedence. The IPCC universal factors are the correct choice only when no national set exists (for example, jurisdictions such as Singapore), or when an explicitly international, source-neutral basis is required. GreenCalculus stores them under the fuels.ipcc.* keyspace so they are always available as the fallback tier.
These factors are on a net (lower) calorific value basis. UK DEFRA factors, by contrast, are on a gross (higher) calorific value basis, and UK gas bills report gross-CV kWh. Net CV is roughly 90% of gross for natural gas and about 94–96% for liquid fuels. Applying an NCV factor to a gross-CV energy figure (or vice-versa) without converting is a systematic error of several percent. State your calorific-value basis explicitly.
Solid fossil fuels
Coal factors vary widely by rank: anthracite and bituminous coals carry more carbon per unit energy than lignite, but lignite's low energy density gives it a high factor per kWh and a comparatively low factor per tonne.
| Fuel | kg CO₂e / kWh (net CV) | kg CO₂e / tonne |
|---|---|---|
| Anthracite | 0.356319 | 2642.7 |
| Other bituminous coal | 0.342999 | 2458.16 |
| Sub-bituminous coal | 0.348399 | 1829.09 |
| Lignite | 0.366039 | 1209.96 |
Liquid & gaseous fossil fuels
Petroleum products and natural gas. Values are given per kWh (net CV) and, where the fuel is conventionally metered by volume or mass, per litre, per cubic metre, or per tonne. A dash indicates the unit is not published for that fuel.
| Fuel | kg CO₂e / kWh (net CV) | kg CO₂e / litre | kg CO₂e / m³ | kg CO₂e / tonne |
|---|---|---|---|---|
| Motor gasoline (petrol) | 0.250355 | 2.29886 | — | 3080.75 |
| Gas / diesel oil | 0.267635 | 2.66085 | — | 3196.75 |
| Jet kerosene | 0.258275 | 2.53109 | — | 3163.87 |
| Other kerosene | 0.259715 | 2.53601 | — | 3159.86 |
| Naphtha | 0.264755 | — | — | 3272.66 |
| Residual fuel oil | 0.279515 | 3.08433 | — | 3136.78 |
| Liquefied petroleum gases (LPG) | 0.227356 | 1.58247 | — | 2987.21 |
| Natural gas | 0.202156 | — | 2.16172 | — |
Biogenic fuels & the CO₂ memo
Biofuels are the one place a fuel-combustion inventory most often goes wrong. The reportable Scope 1 value for a biogenic fuel is only its CH₄ and N₂O — a small number. The much larger CO₂ released when the fuel burns is biogenic: it was recently drawn from the atmosphere, so under the GHG Protocol it is reported as a memo item outside the scopes, not in the Scope 1 total.
| Biogenic fuel | Scope 1 CO₂e / kWh | Scope 1 CO₂e / tonne | Biogenic CO₂ memo / kWh | Biogenic CO₂ memo / tonne |
|---|---|---|---|---|
| Biodiesels | 0.0008748 | 6.561 | 0.25488 | 1911.6 |
| Biogasoline | 0.0008748 | 6.561 | 0.25488 | 1911.6 |
| Biogas / landfill gas | 0.0001962 | — | 0.19656 | — |
| Wood & wood waste | 0.00684 | 29.64 | 0.4032 | 1747.2 |
For biogenic fuels the reportable Scope 1 value is the CH₄+N₂O portion only; the biogenic CO₂ from combustion (the two right-hand columns) is reported as a memo item outside the scopes under the GHG Protocol, because that carbon was recently drawn from the atmosphere. Do not add the memo CO₂ into your Scope 1 total. Biogas / landfill gas is published on a net-CV basis per kWh only.
Application — formula & worked examples
Emissions (kg CO₂e) = Activity data × Emission factor
where activity data is energy on a net-CV basis (kWh), or the fuel's volume (litres, m³) or mass (tonnes), matched to the factor's unit.
Natural gas, by energy. 10,000 kWh (net CV) × 0.202156 = 2,021.6 kg CO₂e. The same gas metered by volume: 1,000 m³ × 2.16172 = 2,161.7 kg CO₂e.
Diesel (gas/diesel oil), by volume. 1,000 litres × 2.66085 = 2,660.9 kg CO₂e. Equivalently by energy at 0.267635 kg/kWh, or by mass at 3,196.75 kg/tonne.
Coal, by mass. 1 tonne of other bituminous coal × 2,458.16 = 2,458.2 kg CO₂e.
Wood (biogenic), by mass. 1 tonne of wood → Scope 1 = 1 × 29.64 = 29.6 kg CO₂e (the CH₄+N₂O only). The biogenic CO₂ — 1,747.2 kg — is reported as a memo item, not added to Scope 1.
Each factor is already aggregated to CO₂e using AR5 GWP-100 (CH₄ = 28, N₂O = 265). If your framework requires AR6, you cannot simply rescale a pre-aggregated CO₂e figure — you would need the separate CO₂, CH₄ and N₂O components. For the overwhelming majority of fuel combustion the CO₂ dominates and the AR5/AR6 difference is immaterial, but the basis must still be disclosed in your methodology.
Framework requirements
Fuel combustion in owned or controlled assets is Scope 1 (direct) under corporate accounting. The IPCC defaults are the accepted Tier-1 method where no more specific factor is available.
| Framework | Where fuel combustion sits | Factor basis |
|---|---|---|
| GHG Protocol Corporate Standard | Scope 1 — stationary & mobile combustion | National factors preferred; IPCC defaults where none exist |
| IPCC 2006 National Inventories | Energy sector (CRF sector 1) | These ARE the Tier-1 default method |
| ISO 14064-1 | Direct GHG emissions (Category 1) | Recognised published factors — IPCC defaults qualify |
| UK SECR / DEFRA | Scope 1 (UK reporters) | Use DEFRA (gross-CV, UK-specific), not these — shown here for contrast |
Common reporting errors
- Mixing net- and gross-CV bases. These factors are net CV; DEFRA and UK gas bills are gross CV. Applying one to the other's energy figure without converting is a systematic several-percent error.
- Using the universal factor where a national one exists. The IPCC defaults are a fallback. For a UK, US or other reporter with a published national dataset, the national factor is more representative and expected.
- Adding biogenic CO₂ into the Scope 1 total. For wood, biodiesel, biogasoline and biogas, only the CH₄+N₂O is reportable in Scope 1; the combustion CO₂ is a memo item outside the scopes.
- Rescaling the pre-aggregated CO₂e to AR6. These are already AR5 CO₂e. You cannot recover an AR6 total by multiplying — you need the separate gas components.
- Unit mismatch. Each factor is tied to a unit (kWh net CV, litre, m³, tonne). Multiplying litres by a per-tonne factor, or gross-CV kWh by a net-CV factor, silently corrupts the result.
- Assuming these are Scope 2 or lifecycle factors. They are Scope 1 combustion only — they do not include the upstream well-to-tank (extraction, refining, transport) emissions of the fuel.
- Treating the coal factors as interchangeable. Anthracite, bituminous, sub-bituminous and lignite differ materially per kWh and per tonne; pick the rank that matches the fuel actually burned.
Methodology, boundaries & uncertainty
What this dataset is. The IPCC 2006 Guidelines Vol.2 (Energy) Tier-1 default combustion factors, pre-aggregated to CO₂e (AR5 GWP-100) on a net calorific value basis, as implemented in the GreenCalculus MasterBrain. CH₄ and N₂O components are the IPCC Table 2.3 defaults (Manufacturing Industries & Construction category).
Boundary. Combustion (Scope 1) only. These factors do not include well-to-tank / upstream fuel-cycle emissions — for a full lifecycle picture, add a WTT factor from a dataset that publishes one.
Rounding policy. Values are reproduced at MasterBrain precision, derived from the IPCC default carbon contents, net calorific values and CH₄/N₂O factors. No further rounding or unit re-basing has been applied.
Uncertainty. IPCC assigns Tier-1 CO₂ factors relatively tight uncertainty (typically within a few per cent, since fuel carbon content is well-characterised), but CH₄ and N₂O defaults carry wide uncertainty (up to an order of magnitude). Because CO₂ dominates the CO₂e total for most fuels, the aggregate factor is robust for screening and Tier-1 inventories; site-specific data is expected where combustion is a material part of the footprint.
Applicability. Global defaults — use where no national factor set applies. Not fuel-batch or plant-specific.
Implementation & provenance chain
- Primary source — IPCC 2006 Guidelines for National Greenhouse Gas Inventories, Volume 2 (Energy): default carbon contents and net calorific values (Vol.2 Ch.1 Tables 1.2–1.4) and default CH₄/N₂O factors (Table 2.3).
- MasterBrain — each fuel is curated under a stable
fuels.ipcc.<fuel>.<unit>key, pre-aggregated to CO₂e (AR5), with its source reference and GHG scope/category; current version v2026.203 (2026-09-22). - REST & CSV — the
/ipcc-fuel-factorsendpoint projects those rows as JSON; the CSV button below serves the identical set. - Calculators — GreenCalculus combustion tools read the same keys as the universal fallback, so a published inventory and this page cannot diverge.
- Update plan — static reference; revalued only on a new IPCC refinement to Vol.2. Any change is logged in the version history and bumps the dataset version.
Data access — REST API & CSV
The full 37-row dataset is available as a machine-readable REST endpoint and as a flat CSV download — the same rows shown above, versioned and citable.
Cache-Control: max-age=3600; X-GC-Version header signals dataset updates. /wp-json/greencalculus/v1/ipcc-fuel-factors
Click to generate ↓
Citation guidance
If you use this dataset, cite the IPCC primary source. The GreenCalculus compilation reference is optional but appreciated.
IPCC (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Volume 2: Energy. Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). IGES, Japan.
IPCC 2006 Guidelines primary citation
Cite this dataset (GreenCalculus compilation). A versioned, machine-readable snapshot of these factors is archived on Zenodo with a citable DOI:
Say, Jeremiah (2026). IPCC universal fuel combustion emission factors — IPCC 2006 Vol.2 (machine-readable) (v2026.59). GreenCalculus. Zenodo. https://doi.org/10.5281/zenodo.21455594
GreenCalculus dataset DOI
Frequently asked questions
They are the IPCC 2006 Guidelines Tier-1 default emission factors for burning fuel — single, globally-applicable CO₂e values built from each fuel's carbon content, calorific value and default CH₄/N₂O factors. Use them when you are reporting fuel combustion in a jurisdiction that has no published national emission-factor dataset, or when you deliberately need an international, source-neutral basis. Where a national dataset exists — UK DEFRA, US EPA and similar — that is more representative of the local fuel mix and takes precedence.
Net (lower) calorific value. This matters: UK DEFRA factors and UK gas bills are on a gross (higher) calorific value basis. Net CV is roughly 90% of gross for natural gas and about 94–96% for liquid fuels. If your energy data is in gross-CV kWh (as UK meters report) and you apply a net-CV factor without converting, you introduce a systematic error of several per cent. Always state your calorific-value basis in the methodology.
AR5 GWP-100 — the values are pre-aggregated to a single CO₂e figure using the AR5 methane (28) and nitrous oxide (265) global warming potentials, the same basis used for national inventory reporting under the Paris Agreement. Because they are already aggregated, you cannot recover an AR6 CO₂e total by rescaling; that would require the separate CO₂, CH₄ and N₂O components. See the IPCC AR6 GWP values dataset for the full set.
Because for a biogenic fuel only the CH₄ and N₂O count in Scope 1 — a small number. The much larger CO₂ released when wood, biodiesel, biogasoline or biogas burns is biogenic (recently drawn from the atmosphere), so under the GHG Protocol it is reported as a memo item outside the scopes, not in the Scope 1 total. The biogenic CO₂ memo values are shown in the biogenic-fuels table and in each row's note. Never add the memo CO₂ into your Scope 1 figure.
Prefer a national dataset where one is published. UK reporters should use DEFRA/DESNZ factors for SECR, ESOS and most UK reporting; US reporters use EPA factors. The IPCC universal factors are the fallback for jurisdictions without a national set (for example Singapore), or where an explicitly international basis is required. GreenCalculus stores them as the fuels.ipcc.* fallback tier so they are always available when a national factor is not.
No. These are combustion factors only — the direct Scope 1 emissions released when the fuel is burned. They do not include the well-to-tank emissions from extracting, refining and transporting the fuel, which are reported separately (typically Scope 3 Category 3). For a full fuel-cycle figure, add a WTT factor from a dataset that publishes one.
These are Tier-1 defaults — the IPCC methodological tier that uses globally-applicable default factors and requires only activity data (fuel quantity). Tier 2 uses country-specific factors (e.g. national carbon contents and calorific values); Tier 3 uses plant- or technology-specific measured data. Tier 1 is appropriate for screening estimates and for inventories where fuel combustion is not a dominant, material source; where it is, higher-tier national or measured factors are expected.
Sixteen fuels across four families: solid fossil (anthracite, other bituminous coal, sub-bituminous coal, lignite); liquid fossil (motor gasoline, gas/diesel oil, jet kerosene, other kerosene, naphtha, residual fuel oil); gaseous fossil (natural gas, LPG); and biogenic (biodiesels, biogasoline, biogas/landfill gas, wood & wood waste). Each is published per kWh (net CV) and, where conventionally metered that way, per litre, per cubic metre or per tonne — 37 factor rows in total.
Version history
| Version | Date | MasterBrain | Summary |
|---|---|---|---|
| 1.0 | 2026-07-20 | v2026.59 | Initial publication. Complete IPCC 2006 Vol.2 universal fuel combustion dataset (37 factors, 16 fuels): solid, liquid, gaseous and biogenic fuels, net-CV basis, AR5 GWP-100. Formula, worked examples, framework mapping, biogenic CO₂ memo treatment, 8-item FAQ, REST + CSV access. |
Put these factors to work
GreenCalculus combustion calculators use these IPCC universal factors as the fallback tier — audit-grade outputs carry the source citation, calorific-value basis, GHG scope/category and MasterBrain version an ISO 14064-3 verifier expects.