Carbon Footprint Calculator
Estimate your annual carbon footprint (in kg CO₂e) based on home energy use, vehicle travel, and diet.
Formulas Used
Electricity: kWh/month × 12 × 0.386 kg CO₂e/kWh
Natural Gas: therms/month × 12 × 5.302 kg CO₂e/therm
Fuel Oil: gallons/month × 12 × 10.16 kg CO₂e/gallon
Vehicle: (miles/year ÷ MPG) × 8.887 kg CO₂e/gallon
Flights: (short flights × 255) + (long flights × 1,620) kg CO₂e
Diet: annual kg CO₂e based on diet type
Total: Sum of all categories
Assumptions & References
- Electricity emission factor: 0.386 kg CO₂e/kWh — US national average (EPA eGRID 2022).
- Natural gas: 5.302 kg CO₂e/therm — EPA Emission Factors for Greenhouse Gas Inventories (2023).
- Fuel oil: 10.16 kg CO₂e/gallon — EPA (2023).
- Gasoline: 8.887 kg CO₂e/gallon — EPA (2023).
- Short-haul flight (<3 hrs): 255 kg CO₂e per flight — DEFRA 2023 aviation factors, economy class, radiative forcing index (RFI) of 1.9 applied.
- Long-haul flight (≥3 hrs): 1,620 kg CO₂e per flight — DEFRA 2023, economy class, RFI 1.9.
- Diet CO₂e values sourced from Poore & Nemecek (2018), Science, and Oxford University Food & Climate Research.
- Global average footprint ~4,700 kg CO₂e/year; US average ~14,000 kg CO₂e/year (Our World in Data, 2022).
- Calculator covers Scope 1 & 2 emissions for energy and direct transport; diet covers food system emissions. Does not include goods, services, or public transit.