Carbon Footprint Calculator
Calculate your personal annual carbon footprint from flights, driving, diet, and home energy.
Did this tool work for you?
How to use this calculator
- 1
Enter the number of flights you take per year and their typical length.
- 2
Enter how many km you drive and your car type.
- 3
Select your diet type and whether you use renewable energy.
- 4
Enter your monthly household energy use and number of members.
- 5
Review your total footprint and compare it to global averages.
Frequently asked questions
What does the footprint include?
Four things: flights, car driving, diet and home energy. Public transport, shopping, goods, waste, heating fuels measured other than in kWh, and anything else you buy are not counted, so the total is a partial picture, not a full inventory.
How are flights counted?
The number of flights you enter is multiplied by 0.255 tonnes for short-haul, 0.8 tonnes for long-haul, or 0.5275 tonnes for the mixed setting, which is the average of the two. Two mixed flights show as 1.06 tonnes. The tool does not know the distance, so decide beforehand whether a return trip counts as one flight or two.
How is car travel calculated?
Kilometres per year × a per-kilometre factor, divided by 1,000 to give tonnes. The factors in this tool are 0.192 kg for petrol, 0.171 for diesel, 0.107 for hybrid and 0.053 for electric, and zero for no car. 15,000 km in a petrol car gives 2.88 tonnes.
How is diet counted?
As a fixed annual amount chosen from five levels: 3.3 tonnes for meat heavy, 2.5 for average omnivore, 1.9 for low meat, 1.5 for vegetarian and 1.1 for vegan. Portion sizes, food waste and where the food comes from are not entered.
How is home energy calculated, and why is it divided?
Monthly kWh × 12 × 0.2 kg per kWh, multiplied by the renewable setting (1 for none, 0.5 for partial, 0 for 100% renewable), then divided by household members. Dividing assigns you a share of the household’s use. Flights, car driving and diet are not divided: they are treated as yours alone.
Where do the comparison lines come from?
The 4.8-tonne world figure, the 16-tonne US figure and the 21 kg-per-tree-per-year used for the tree count are numbers built into this tool. They are not refreshed and real averages differ by year and by source, so treat them as rough reference points.
How reliable are the emission factors?
Treat them as estimates. Real values vary by country, year and supplier, and the figures built into this tool are single averages. A coal-heavy grid and a hydro-heavy grid, for instance, give very different results for the same kWh, but the tool uses one number for both. Negative entries are treated as zero, and household members are never fewer than 1.
Carbon footprint calculator: flights, car, diet and home energy
How to use the carbon footprint calculator
Use this carbon footprint calculator to estimate your annual CO₂ emissions from home energy, transport, diet, and consumer spending. Enter your monthly usage in each category above and see your total footprint in tonnes of CO₂ equivalent per year, along with a comparison to your country's average. Free and instant.
How the carbon footprint calculator works
The carbon footprint calculator applies IPCC and DEFRA emission factors to your entered energy, transport, and lifestyle data to estimate annual CO₂e emissions. Country averages are sourced from IEA and World Bank datasets. All calculations run locally in your browser — no personal data is sent to any server.
How the total is built
The calculator adds four lines expressed in tonnes of CO₂ per year. Flights depend on how many you take and whether they are short or long, driving on distance and fuel type, diet on one of five categories, and home energy on your monthly kWh, your renewable tariff and the people sharing the home. All the emission factors are the figures built into this tool, so the total is best read as an arithmetic estimate and not a measured footprint.
| Source | Figure used | Applied as |
|---|---|---|
| Short-haul flight | 0.255 t each | × number of flights |
| Long-haul flight | 0.8 t each | × number of flights |
| Petrol / diesel car | 0.192 / 0.171 kg per km | × km per year |
| Hybrid / electric car | 0.107 / 0.053 kg per km | × km per year |
| Diet | 3.3 / 2.5 / 1.9 / 1.5 / 1.1 t | Meat heavy to vegan, per year |
| Home energy | 0.2 kg per kWh | × 12 × renewable factor ÷ members |
Worked example: the default profile
Two mixed flights, 15,000 km in a petrol car, an average omnivore diet and 350 kWh a month shared between two people with no renewable tariff total 6.86 tonnes. Flights contribute 1.06, the car 2.88, diet 2.50 and home energy 0.42. That is 2.06 tonnes above the built-in world figure of 4.8 and 9.14 below the built-in US figure of 16. The tool puts the offset at 326 trees for one year.
| Line | Tonnes CO₂ per year |
|---|---|
| Flights (2, mixed) | 1.06 |
| Car (15,000 km, petrol) | 2.88 |
| Diet (average omnivore) | 2.50 |
| Home energy (350 kWh a month, 2 people) | 0.42 |
| Total | 6.86 |
Worked examples: high and low profiles
Six long-haul flights, 20,000 km in a diesel car, a meat-heavy diet and 500 kWh a month for one person come to 12.72 tonnes: 4.80 from flights, 3.42 from the car, 3.30 from diet and 1.20 from the home. At the other end, a vegan with no flights, no car and a 100% renewable tariff in a three-person household has only the diet line, 1.10 tonnes. A family of four with four short-haul flights, an electric car at 10,000 km, a vegetarian diet and a partly renewable tariff totals 3.15 tonnes.
| Profile | Flights | Car | Diet | Home | Total |
|---|---|---|---|---|---|
| 6 long-haul, diesel 20,000 km, meat heavy, 500 kWh, 1 person | 4.80 | 3.42 | 3.30 | 1.20 | 12.72 |
| Vegan, no car, no flights, renewable, 3 people | 0.00 | 0.00 | 1.10 | 0.00 | 1.10 |
| 4 short-haul, electric 10,000 km, vegetarian, partial renewable, 4 people | 1.02 | 0.53 | 1.50 | 0.10 | 3.15 |
What moves the total most
In these profiles the biggest single lines are flights, driving and diet, with home energy smaller once it is shared. Because diet is a flat value per category, switching categories changes the total by a fixed amount regardless of anything else you enter. The renewable tariff setting only affects the home energy line. Compare scenarios by changing one input at a time.
Limits
The tool does not calculate emissions of goods, services, public transport or waste, does not scale diet by portion, and uses one grid factor for home energy everywhere. It states results in tonnes of CO₂ only and makes no claim about what any reduction or offset achieves beyond the arithmetic shown.
Learn more from an authoritative source:
WikipediaHousehold Emissions Calculator
Calculate the carbon emissions and energy costs from your home electricity and gas usage.
Water Usage Calculator
Calculate your household's daily water consumption in litres and your estimated annual water bill.
Recycling Impact Calculator
See the environmental savings from recycling household materials including CO₂, energy, and water.
Carbon Offset Calculator
Calculate the cost to offset a given carbon footprint through different verified offset programmes.
Renewable Energy Payback Calculator
Calculate the payback period, 25-year savings, and ROI for home solar panels or a small wind turbine.
Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →