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Carbon · Converter

Electricity CO₂ Calculator

Convert electricity use (kWh) into emissions with an emission factor for your grid, region or supplier. The answer is only as specific as the factor: its geography, year, gas basis (CO₂ or CO₂e) and boundary carry straight into the result.

United Kingdom, 2025 factor set, CO₂e. Location-based, Scope 2 electricity generated (UK grid average). Excludes transmission and distribution losses, which the same set reports separately (0.01853 kg CO₂e/kWh). Source: UK Government GHG Conversion Factors for Company Reporting 2025 (DESNZ), "UK electricity" factor.

Estimated emissions

620 kg CO₂e

= 0.62 tonnes CO₂e

3,500 kWh × 0.177 kg/kWh

Covers only the boundary of the United Kingdom factor described on the left.

Formula

emissions (kg) = kWh × factor (kg/kWh)

kg/kWh = g/kWh ÷ 1,000 = kg/MWh ÷ 1,000 = lb/MWh × 0.45359237 ÷ 1,000

tonnes = kg ÷ 1,000

The preset factors are annual averages. Grid intensity changes by hour and by region, so a short period or a specific region can differ from the average. The electricity CO₂ guide explains how to choose a factor and interpret the result. Preset sources are documented on the sources and methodology page; more carbon tools are in the Carbon Footprint hub.

FAQ

How is kWh converted to CO₂?
Multiply the electricity used (kWh) by an emission factor expressed per kWh. Example: 3,500 kWh × 0.177 kg CO₂e/kWh (UK Government 2025 factor) = 619.5 kg CO₂e. The result covers only what that factor covers, for the same geography and year.
Which emission factor should I use?
For "what were the emissions of the electricity I used" use a location-based grid average for your country or region and year, from an official source such as your government's conversion factors or, in the US, your EPA eGRID subregion. If you are reporting a supplier or tariff, use the supplier-specific (market-based) factor your supplier publishes. Do not mix the two in one total.
Should the result say CO₂ or CO₂e?
Use the basis of your factor. CO₂ counts carbon dioxide only; CO₂e also includes other greenhouse gases such as methane and nitrous oxide, weighted by their warming effect. Both presets on this page are CO₂e factors. Choose the matching basis when you enter your own factor.
Can I use IPCC lifecycle figures as a grid factor?
No. IPCC lifecycle medians describe generation technologies (for example, wind or gas power), not the average electricity of any country's grid in a given year. Use a published grid factor instead.

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