Carbon Footprint Calculator
Estimate your annual CO₂ emissions from home energy and travel, by source
Related calculators
All energy- EV Savings CalculatorCompare electric vs gas fuel cost per year, per mile, and lifetime
- Solar Panel CalculatorSystem size, cost after incentives, savings, and payback from your bill
- HVAC SEER Savings CalculatorCooling energy and cost saved by upgrading to a higher SEER
- LED Savings CalculatorEnergy, money, and CO2 saved by switching bulbs to LED
- Heat Pump Savings CalculatorHeating savings vs electric resistance, gas, oil, or propane
- Home Battery Backup CalculatorBackup runtime during an outage and batteries needed for a target
Quick summary
Enter your monthly electricity and natural gas use, weekly driving and vehicle MPG, and yearly flights to estimate your annual carbon footprint in tonnes of CO₂, broken down by source and compared to the ~16-tonne US per-person average. It uses EPA-style emission factors (0.386 kg CO₂ per kWh of grid power, 8.89 kg per gallon of gasoline). It covers home energy and travel — the biggest household levers — but not diet, goods, or services.
Reviewed by Simple Calculators TeamLast reviewed
How to use this calculator
- Enter the inputs requested by the calculator.
- Choose the units or options that match your situation and review the assumptions.
- Run or update the calculation to see the result.
- Review the result, breakdown, and formulas shown on the page.
- Check the inputs, units, dates, and limitations before saving or sharing the result.
Frequently asked questions
How do I calculate my carbon footprint?
Multiply each activity by its emission factor and add them up: electricity (kWh × 0.386 kg), natural gas (therms × 5.3 kg), driving (gallons × 8.89 kg), and flights (roughly 500 kg per short round trip, 1,800 kg per long one). This calculator does it from simple monthly and yearly inputs.
What is the average carbon footprint?
The US average is roughly 16 tonnes of CO₂ per person per year — among the highest in the world — versus a global average near 4–5 tonnes. Climate targets imply getting personal footprints down toward ~2 tonnes by mid-century. The calculator shows where you stand against the US figure.
What has the biggest impact on my footprint?
For most households, it's driving, home heating, electricity, and air travel — in varying order. A single long-haul round-trip flight (~1.8 tonnes) can rival months of home energy. The breakdown here highlights your largest source so you can target the changes that actually move the needle.
Why does electricity's impact vary by region?
Because grid mixes differ. A kWh from a coal-heavy grid emits far more than one from hydro, nuclear, or solar. This tool uses the US average (0.386 kg/kWh); if your utility is especially clean or dirty, your real electricity emissions will be lower or higher than shown.
Key terms
- Emission Factor
- CO₂ released per unit of activity, e.g. kg per kWh or per gallon.
- CO₂e
- Carbon dioxide equivalent — a common unit combining all greenhouse gases.
- Tonne
- 1,000 kg; the usual unit for annual carbon footprints.
- Grid Intensity
- CO₂ per kWh of your local electricity, which varies by region.
Methodology, sources & limitations
This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.
For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.