How UK carbon emissions are measured
Carbon footprint is measured in metric tonnes of carbon dioxide equivalent (tonnes CO2e) using greenhouse gas reporting figures published by the UK Department for Energy Security and Net Zero (DESNZ).
Grid electricity is calculated at 0.207 kg CO2e/kWh, natural gas at 0.183 kg CO2e/kWh, average car travel at 0.27 kg CO2e/mile, alongside baseline consumption for goods and food.
Worked example
For a typical UK home consuming 2,900 kWh electricity and 12,000 kWh gas, driving 6,500 car miles and taking 4 flight hours per year:
Home energy produces 2.80 tonnes CO2e, transport produces 2.06 tonnes CO2e, and baseline goods add 2.00 tonnes, resulting in 6.86 tonnes CO2e total annual emissions (below the UK national average of 8.2 tonnes).
Inputs for the carbon footprint calculator
Annual electricity consumption
Your annual domestic electricity usage in kWh (UK average is ~2,900 kWh/yr).
Annual natural gas consumption
Your annual domestic natural gas usage in kWh (UK average is ~12,000 kWh/yr).
Annual vehicle mileage
Total miles driven in private petrol or diesel cars each year (UK average is ~6,500 miles).
Annual commercial flight hours
Total hours flown on commercial passenger airlines over the course of the year.
CALCULATOR QUESTIONS
Carbon footprint calculator questions
What is the average UK carbon footprint per person?
The average UK resident generates approximately 8.2 tonnes of CO2 equivalent emissions per year across home energy, transport and consumption.
How many trees does it take to absorb 1 tonne of CO2?
A healthy mature tree absorbs approximately 22 kg of CO2 per year, meaning around 45 trees are required to offset 1 metric tonne of CO2 annually.