Carbon Footprint Estimator

Estimate your annual carbon footprint in tonnes of CO2e from car and plane travel, home heating, diet, and general consumption, broken down by category and compared to national averages and the Paris Agreement target.

By Marshkalk

Fill in your yearly transport, home heating, diet, and general consumption habits to get an estimate of your carbon footprint in tonnes of CO2 equivalent per year (tCO2e/year).

Transport

Housing

Diet

Goods and consumption

The average carbon footprint in the UK and why it matters

A personal carbon footprint adds up the greenhouse gas emissions caused by an individual's transport, home energy use, food, and general consumption over a year, expressed in tonnes of CO2 equivalent (tCO2e), a unit that converts other gases such as methane into the warming effect of the same mass of CO2. Estimates for the average UK resident vary by method and by which supply-chain emissions are counted, but commonly sit between 5.5 and 8.5 tCO2e per year according to DEFRA greenhouse gas conversion factors and academic consumption-based studies (2023-2024 figures), a level well above the roughly 2 tCO2e per year per person the Paris Agreement implies as a global fair share by 2050 to keep warming under 1.5C. This calculator breaks the estimate into transport, housing, diet, and consumption so you can see which habits contribute the most, and it uses the UK electricity grid mix (increasingly gas and wind) as the default assumption for electric heating and cars.

Emission factors used in this estimate

ItemApproximate factorBasis
Petrol car0.193 kgCO2e/kmDEFRA average car factor
Diesel car0.176 kgCO2e/kmDEFRA average car factor
Electric car0.060 kgCO2e/kmUK grid electricity mix, well-to-wheel
Short-haul flight0.258 kgCO2e/km per passengerIncludes radiative forcing uplift
Long-haul flight0.152 kgCO2e/km per passengerIncludes radiative forcing uplift
Bus or train0.035 kgCO2e/kmAverage UK public transport occupancy
Gas heating30 kgCO2e/m2/yearAverage UK dwelling gas use
Meat-daily diet2.5 tCO2e/yearUK diet-related food emissions studies

What this calculator cannot do

This tool gives a simplified estimate, not a full carbon assessment. It uses average national emission factors rather than the exact carbon intensity of your electricity supplier, the specific model of your car or aircraft, or the origin of the food and goods you buy, all of which can shift the real figure noticeably in either direction. It also does not account for one-off large purchases, home renovation, or the indirect emissions from public services and infrastructure that a full GHG Protocol scope 1, 2, and 3 assessment would include. Treat the result as a starting point for spotting your largest sources of emissions, not as a certified figure for offsetting or reporting purposes. For a related household calculation, the Electrical Load Calculator can help estimate the power draw behind your electricity bill.

A worked example

Someone driving a petrol car 10,000 km a year (10,000 x 0.193 = 1.93 tCO2e), taking one short-haul return flight of 2,000 km (2,000 x 0.258 = 0.52 tCO2e), heating an 80 m2 gas-heated flat (80 x 30 / 1000 = 2.4 tCO2e), eating meat daily (2.5 tCO2e), and keeping a medium consumption level (1.6 tCO2e) reaches a total of about 8.95 tCO2e per year, close to the UK average. Cutting the flight and switching to an occasional-meat diet would bring that estimate down by roughly 1.3 tCO2e per year, which shows how transport and diet choices tend to move the total the most for a typical household.