Carbon Emissions Calculator
Estimate the annual carbon footprint of a facility from its electricity and natural gas usage, using EPA eGRID regional emission factors and standard GHG equivalencies.
Framing only — does not change the calculation.
Not sure which region applies to you? Look up your exact eGRID subregion using EPA’s Power Profiler tool by ZIP code. These are representative regional averages.
kWh × grid factor × (1 − renewable %)
electricity + natural gas
metric tons × 2.2046
metric tons ÷ 4.6 t per vehicle/yr
metric tons × 16.5 seedlings per t
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →Location is a carbon lever, not just a cost lever. The exact same 500,000 kWh of annual electricity use produces roughly 4x more emissions on the Upper Midwest’s coal-heavy grid than it does in Upstate New York’s largely nuclear-and-hydro grid. Where a facility sits -- not just how efficiently it runs -- can be one of the single biggest factors in its carbon footprint. That’s the same geography that determines time-to-power and electricity cost; carbon intensity moves with it too.
How carbon emissions are calculated
Electricity-related emissions start with your annual usage in kWh, multiplied by your grid region’s emission factor in kg CO2e per kWh (drawn from EPA eGRID2023 regional averages), then reduced by any renewable energy or REC coverage you apply — the formula is kWh × factor × (1 − renewable %). Natural gas emissions, when included, are calculated separately using the EPA GHG Emission Factors Hub combustion constant of 5.31 kg CO2e per therm, then added to the electricity total.
The combined total is reported in metric tons CO2e (kg ÷ 1,000) and in pounds (kg × 2.2046). For context, the total is also expressed as everyday equivalencies using EPA Greenhouse Gas Equivalencies Calculator constants: gasoline-powered vehicles driven for one year (metric tons ÷ 4.6 t CO2e per vehicle per year) and tree seedlings grown for 10 years (metric tons × 16.5 seedlings per metric ton).
CO2e — carbon dioxide equivalent — converts other greenhouse gases released during generation (methane, nitrous oxide) into the amount of CO2 that would cause the same warming, so the total reflects full climate impact, not just CO2 alone. This tool uses official EPA regional averages and is useful for benchmarking and general awareness; a professional carbon audit would account for your specific utility’s generation mix, transmission losses, and Scope 3 emissions.