Carbon emissions by energy source, using EPA factors
Greenhouse gas accounting is arithmetic. Multiply how much of each energy source you used by its emission factor and add the results. The hard parts are choosing defensible factors and deciding where your boundary sits. This tool takes the numbers already printed on your utility bills and fuel invoices and returns a footprint in pounds and metric tons of CO₂e.
| Energy source | Factor applied | Scope |
|---|---|---|
| Electricity | 0.85 lb CO₂e/kWh | Scope 2 (indirect) |
| Natural gas | 11.7 lb CO₂e/therm | Scope 1 (direct) |
| Diesel | 22.5 lb CO₂e/gal | Scope 1 (direct) |
| Gasoline | 19.6 lb CO₂e/gal | Scope 1 (direct) |
Electricity is Scope 2, emissions released at a power plant on your behalf rather than at your site. Fuel burned in your boilers and vehicles is Scope 1, direct emissions. The two are shown separately because the levers differ. Scope 2 shrinks through efficiency and renewable procurement, while Scope 1 shrinks through fuel switching and equipment upgrades.
Using 10,000 kWh, 500 therms, 100 gallons of diesel and 200 gallons of gasoline gives about 20,520 lb, or 9.31 metric tons of CO₂e. For scale, EPA equates 4.6 metric tons to one gasoline passenger vehicle driven for a full year, so that footprint is roughly two cars.
The electricity factor here is a national average. Actual grid intensity varies enormously by eGRID subregion, from well under half the average in hydro and nuclear heavy regions to far above it elsewhere, so use your subregion factor for any real inventory. Values reflect the EPA GHG Emission Factors Hub as of September 2026. For regulatory reporting or a verified inventory, apply the current published factors and have the work reviewed by a qualified professional.
Frequently Asked Questions
Because the generation mix changes. More renewables and nuclear pull the factor down, more coal pushes it up. EPA republishes eGRID periodically, so pull the current factor for your subregion.
Scope 3 covers purchased goods, freight, commuting, waste and the rest of the value chain. Data is harder to obtain, so most organizations follow a dedicated protocol and expand category by category, starting with the largest.