Scope 1 Emission Factors: 2024 Reference Table

Every emission factor you need for a GHG Protocol Scope 1 inventory. Sourced, versioned, and copy-paste ready.
Last updated: March 2026 Sources: EPA GHG EF Hub 2024, DEFRA 2025, IPCC AR6 Reading time: 8 min
On this page
Stationary Combustion Mobile Combustion (Fleet) Fugitive Emissions (Refrigerants) Scope 2 Grid Factors by Region How to Use These Factors Source Documentation

If you're building a Scope 1 emissions inventory for the first time, you need two things: your activity data (how much fuel you burned, how much refrigerant you lost) and the right emission factors to convert that activity into tCO2e.

This page gives you the emission factors. Every value is sourced from an authoritative database, with the publication year and methodology noted. You can use these directly in your GHG inventory — no lookup required.

How to read this table: Multiply your activity data (gallons of fuel, therms of gas, kg of refrigerant) by the emission factor. Divide by 1,000 to convert kgCO2e to tCO2e. Example: 10,000 gallons of diesel x 10.21 kgCO2e/gal = 102,100 kgCO2e = 102.1 tCO2e.

Stationary Combustion

Boilers, furnaces, generators, and other fixed equipment that burns fuel on your premises.

Fuel TypeCommon UseUnitEF (kgCO2e/unit)Source
Natural gasBoilers, furnaces, heatingtherm5.3EPA GHG EF Hub 2024
Diesel / distillate fuel #2Backup generatorsgallon10.21EPA GHG EF Hub 2024
Fuel oil #6 (residual)Industrial boilersgallon11.27EPA GHG EF Hub 2024
Propane (LPG)Heating, forkliftsgallon5.72EPA GHG EF Hub 2024
Coal (bituminous)Industrial processeskg2.23EPA GHG EF Hub 2024
Wood / biomassBiomass boilerskg1.65DEFRA 2025
KeroseneJet fuel, heatinggallon9.75EPA GHG EF Hub 2024

Mobile Combustion (Fleet)

Company-owned or company-controlled vehicles. If you reimburse employees for mileage, that's Scope 3 (Category 7), not Scope 1.

Fuel TypeVehicle TypeUnitEF (kgCO2e/unit)Source
GasolinePassenger vehicles, light trucksgallon8.78EPA GHG EF Hub 2024
DieselTrucks, heavy equipmentgallon10.21EPA GHG EF Hub 2024
LPG / PropaneForklifts, fleet vehiclesgallon5.68EPA GHG EF Hub 2024
CNG (compressed natural gas)CNG fleet vehiclestherm5.3EPA GHG EF Hub 2024
Fleet tip: If you track mileage instead of fuel purchases, you'll need a vehicle-specific EF (kgCO2e per mile). These vary significantly by vehicle class. The EPA provides per-mile factors in Table 5 of the GHG EF Hub. For a quick estimate: passenger cars average ~0.35 kgCO2e/mile; light trucks ~0.45; heavy-duty trucks ~1.6.

Fugitive Emissions (Refrigerants)

Refrigerant leakage from HVAC systems, chillers, and cold storage. These use Global Warming Potential (GWP) values instead of combustion factors — 1 kg of leaked refrigerant is multiplied by its GWP to get kgCO2e.

RefrigerantCommon EquipmentUnitGWP (kgCO2e/kg)Source
R-410ACommercial HVACkg2,088IPCC AR6 (GWP-100)
R-134aVehicle AC, chillerskg1,430IPCC AR6 (GWP-100)
R-22 (HCFC-22)Legacy HVAC systemskg1,810IPCC AR6 (GWP-100)
R-407CCommercial ACkg1,774IPCC AR6 (GWP-100)
R-404ASupermarket refrigerationkg3,922IPCC AR6 (GWP-100)
R-32Newer residential ACkg675IPCC AR6 (GWP-100)
Why refrigerants matter: A single R-404A leak of 10 kg = 39.2 tCO2e. That's equivalent to burning 3,840 gallons of diesel. Refrigerant management is often the highest-impact Scope 1 reduction lever that companies overlook.

Scope 2: Grid Emission Factors by Region

While technically Scope 2, you need these to complete your inventory. Multiply your facility's annual kWh by the regional grid factor.

RegionGridEF (kgCO2e/kWh)Source
US AverageNational0.386EPA eGRID 2024
US Northeast (NPCC)New England, NY0.210EPA eGRID 2024
US Midwest (RFCW)OH, IN, WV0.440EPA eGRID 2024
US Southeast (SRMV)LA, MS, AR0.380EPA eGRID 2024
US California (CAMX)CA0.225EPA eGRID 2024
US Northwest (NWPP)WA, OR, ID0.280EPA eGRID 2024
US Texas (ERCT)TX0.370EPA eGRID 2024
United KingdomNational0.207DEFRA 2025
EU AverageEU-270.230IEA 2024
GermanyNational0.350IEA 2024
FranceNational0.052IEA 2024
AustraliaNational0.680IEA 2024
JapanNational0.450IEA 2024
IndiaNational0.720IEA 2024
ChinaNational0.555IEA 2024

How to Use These Factors

The formula

tCO2e = Activity Data x Emission Factor / 1,000

Example: Your fleet burned 25,000 gallons of diesel last year.

25,000 gal x 10.21 kgCO2e/gal = 255,250 kgCO2e = 255.3 tCO2e

Where to get your activity data

Fuel purchases: accounts payable, fuel card statements, utility bills. Refrigerant: HVAC maintenance logs, refrigerant purchase/disposal records. Electricity: utility bills (kWh per facility per month). If you have cost data but not consumption data, your utility provider can convert. Most utilities will provide a 12-month usage summary on request.

Which factors to use when

Use the most specific factor available. If you know your eGRID subregion, use that instead of the US average. If your supplier provides a product-specific EF, use that instead of the EPA default. Document your choice — your auditor will ask why you picked each factor.

When factors change

EPA updates the GHG EF Hub annually (usually Q1). DEFRA publishes updated factors each June. IEA updates grid factors in their annual World Energy Outlook. If you're reporting year-over-year, use the factor that corresponds to your reporting period — don't retroactively apply new factors to old data unless doing a base-year recalculation per GHG Protocol guidance.

Source Documentation

Every factor on this page can be independently verified:

EPA GHG Emission Factors Hub (2024): epa.gov/climateleadership/ghg-emission-factors-hub. Table 1 (stationary), Table 2 (mobile), Table 5 (per-mile), Table 10 (electricity).

DEFRA Greenhouse Gas Reporting Conversion Factors (2025): gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2025. Updated annually by UK BEIS.

IPCC AR6 GWP Values: Chapter 7, Table 7.SM.7. 100-year GWP values used throughout (GWP-100).

EPA eGRID (2024): epa.gov/egrid. Subregion-level emission rates for US electricity.

IEA Emission Factors (2024): iea.org/data-and-statistics. Country-level grid emission factors.

Need help building your inventory?

Emberglow's portal auto-suggests these factors when you select a source type. Start your Scope 1 baseline in under 30 minutes.

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