CARBON FOOTPRINT CALCULATOR
Measure the Carbon.
Change the Outcome.
Estimate your annual carbon footprint from travel, home energy, and diet - using published emission factors, calculated entirely in your browser.
Car Travel
Electric vehicle emissions use the electricity grid region you select in Home Electricity below.
Flights
Round-trip distance flown per year. Roughly: Singapore-Bangkok return ≈ 3,000 km, Singapore-London return ≈ 21,000 km.
Home Electricity
Diet
Everything is calculated locally in your browser. Nothing you enter is uploaded or sent to analytics.
Methodology & sources
- Car (petrol/diesel average): 0.170 kg CO2e/km - UK DESNZ/DEFRA greenhouse gas conversion factors, via Our World in Data.
- Car (electric): assumes 0.18 kWh/km (a typical efficiency figure for electric cars), multiplied by your selected grid's electricity factor.
- Flights, short/medium-haul (economy): 0.156 kg CO2e/km - UK DESNZ/DEFRA, via Our World in Data.
- Flights, long-haul (economy): 0.117 kg CO2e/km - UK DESNZ/DEFRA conversion factors.
- Electricity grid factors: Global average 0.445 kg CO2/kWh (IEA, 2024 data); United States 0.394 kg CO2/kWh (US EPA, delivered electricity); European Union average 0.175 kg CO2/kWh (IEA, 2024 data); Singapore 0.471 kg CO2/kWh (Singapore power sector carbon intensity, 2023).
- Diet: annual figures derived from Scarborough et al. (2014), "Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK," Climatic Change - a peer-reviewed dietary greenhouse gas study.
- Global average comparison: ~4.9 tonnes CO2 per person per year (Our World in Data / Worldometer, 2024) - this covers fossil CO2 from transport, electricity, and heating only, and does not include food or land-use emissions, so it is not a like-for-like total against this calculator's diet-inclusive result.
This is an estimate for general awareness, not a certified carbon accounting tool. Real-world emissions vary by vehicle, flight routing, local grid mix, and individual diet composition.
About Carbon Footprints
What is CO2e?
CO2e (carbon dioxide equivalent) converts all greenhouse gases - not just CO2, but methane, nitrous oxide, and others - into a single comparable number based on their warming effect.
How accurate is this?
It's a reasonable estimate built on published emission factors, not a certified measurement. Actual emissions depend on your specific vehicle, flight routing, exact local grid mix, and diet composition.
What reduces a footprint the most?
For most people, the biggest single levers are usually flying less (long-haul flights add up fast), driving less or going electric on a cleaner grid, and shifting away from high-meat diets.
Is my data saved anywhere?
Only on this device, if at all. Your inputs are kept in your browser's local storage purely so the form doesn't reset if you reload the page - they are never uploaded or sent to analytics.