What is the Electricity Carbon Footprint Calculator?
This tool estimates the carbon dioxide (CO₂) emissions produced by your electricity consumption. Because electricity is generated by a mix of sources — coal, gas, nuclear, hydro, wind and solar — every kilowatt-hour (kWh) carries a different amount of CO₂ depending on your local grid. This is captured by the emission factor, measured in kilograms of CO₂ per kWh. The calculator is universal: enter the emission factor that applies to your country or supplier.
How to use it
Enter the electricity you used in kWh (e.g. a monthly bill figure), your grid emission factor in kg CO₂/kWh, and the number of periods to multiply by — for example 12 to turn a monthly figure into an annual total. The result shows total CO₂ in kilograms and tonnes, plus emissions per single period.
The formula explained
The core equation is simply:
$$\text{CO}_2\ (\text{kg}) = \text{kWh} \times \text{emission factor}$$
To cover several billing periods, the result is multiplied by the number of periods \(n\). Dividing kilograms by 1,000 gives the figure in metric tonnes, the unit most often used for annual footprints.
Worked example
Suppose your home uses 900 kWh per month and your grid emission factor is 0.4 kg CO₂/kWh. Per month that is $$900 \times 0.4 = 360 \text{ kg CO}_2.$$ Over 12 months: $$360 \times 12 = 4{,}320 \text{ kg},$$ or 4.32 tonnes of CO₂ per year.
FAQ
Where do I find my emission factor? National energy or environment agencies publish grid average factors; values typically range from about 0.02 kg/kWh (very clean grids) to over 0.8 kg/kWh (coal-heavy grids).
Does this include heating or transport? No — this calculator covers electricity only. Add separate estimates for gas, fuel and travel for a full footprint.
Why report tonnes? Annual and national carbon targets are usually expressed in tonnes of CO₂, so the conversion helps you compare against benchmarks.
