Electricity CO₂ Calculator: kWh to CO₂
Convert electricity consumption in kWh into estimated carbon dioxide emissions. Use a factor matching your electricity supply and year. This tool measures generation-related CO₂, not the full lifecycle of electricity infrastructure.
How to convert kWh to CO₂
Annual kg CO₂ = annual kWh × kg CO₂/kWh. There is no universal conversion: the emission factor depends on the electricity supply, location, dataset and year. With the January 2025 Hub preset, 1 kWh corresponds to about 0.350 kg CO₂.
kWh to CO₂ conversion examples
Using the same January 2025 US Hub factor of 0.349946513455 kg CO₂/kWh:
| Annual electricity | kg CO₂/year | Metric tonnes CO₂/year |
|---|---|---|
| 1 kWh | 0.35 | 0.0003 |
| 100 kWh | 34.99 | 0.0350 |
| 500 kWh | 174.97 | 0.1750 |
| 1,000 kWh | 349.95 | 0.3499 |
| 5,000 kWh | 1749.73 | 1.7497 |
| 10,000 kWh | 3499.47 | 3.4995 |
Why do the national presets differ?
The EPA January 2025 Hub and the later eGRID2023 revision 2 are distinct published releases. This tool labels both so an earlier example can be reproduced. Choose a factor matching your reporting context; these presets are not live electricity-intensity measurements.
Source for revision 2 subregion factors. Values in lb CO₂/MWh are converted with kg/kWh = lb/MWh × 0.45359237 ÷ 1,000.
Can I use a CO₂e factor?
This tool labels its result CO₂. To preserve that meaning, use a CO₂-only factor. A CO₂e factor accounts for additional gases and needs a different result interpretation. Neither result is automatically a verified carbon offset.
Formula and example
kg CO₂ = electricity in kWh × kg CO₂ per kWh. At the US preset, 1,000 kWh produces an estimate of 349.95 kg CO₂. Choose Annual total for a full year or Monthly amount to multiply by 12. The result is always labeled as an annual estimate. For MWh, the tool first multiplies consumption by 1,000. For a factor in g CO₂/kWh, it first divides the factor by 1,000.
Choosing the right factor
Find a published generation or supplier CO₂ factor with a clear geographic scope and year. If your factor is in grams per kWh, choose g CO₂/kWh as the emission factor unit and enter the number as published. If you choose kg CO₂/kWh instead, divide the gram value by 1,000 first. Do not do both. Do not enter a CO₂e factor into a CO₂-only comparison without changing the interpretation.
What is excluded?
The default excludes transmission losses, fuel extraction, power-plant manufacturing and non-CO₂ gases. It is an accounting estimate, not a forecast of marginal emissions avoided by switching off an appliance. For shared housing, divide an annual household result by the number of people only if equal allocation fits your purpose.
Source: EPA 2025 Hub, table 6. Combine electricity, heating and travel in the main calculator.
Updated 30 October 2026 · Climate Calculator.
No comments:
Post a Comment