Carbon Footprint Calculator (household)
Estimate annual tCO₂e from electricity, gas, driving, flights, and diet — EPA / DEFRA emission factors.
Result
- Electricity900 kWh/mo × 12 × 0.385 kg/kWh (EPA eGRID US avg)4.158 t
- Natural gas60 therms/mo × 12 × 5.31 kg/therm (EPA)3.823 t
- Driving (gasoline)12000 mi / 27 MPG = 444 gal × 8.887 kg/gal (EPA)3.950 t
- Flights2 short (200kg ea) + 1 long (900kg ea) (DEFRA 2024)1.300 t
- Diet (omnivore, per person)Our World in Data, EAT-Lancet 2024 dataset2.50 t/yr
- — Household totals —
- Household total18.23 tCO₂e/yr
- Per-capita9.12 tCO₂e/yr
- — Benchmarks —
- US per-capita avg13.9 t (EPA 2022)
- EU per-capita avg7.5 t
- Global per-capita avg4.7 t
- IPCC 1.5°C target 20502 t/capita
Step-by-step
- Electricity = 900 kWh/mo × 12 × 0.385 kg/kWh = 4,158 kg = 4.158 t.
- Gas = 60 therms/mo × 12 × 5.31 kg/therm = 3,823 kg = 3.823 t.
- Driving = 12000 mi / 27 MPG × 8.887 kg/gal = 3,950 kg = 3.950 t.
- Flights = 2·200 + 1·900 = 1,300 kg = 1.300 t.
- Diet (omnivore) = 2.5 t × 2 people = 5.00 t.
- Per-capita = household / 2 = 9.115 t.
How to use this calculator
- Pull monthly kWh and therms from your utility bills (the values printed near "current month usage").
- Set vehicle miles from odometer changes year-over-year; MPG from EPA window-sticker or fueleconomy.gov.
- Count actual flights from your boarding-pass archive — under-reporting is the biggest source of footprint-tool error.
- Pick diet honestly — heavy-meat vs omnivore is a ~30% difference; vegetarian vs vegan is small in the EAT-Lancet model.
- Compare per-capita number to US (14), EU (7.5), global (5), and IPCC 2050 (2) benchmarks.
About this calculator
A rough household carbon footprint computed from the six biggest direct emitters: electricity (kWh × EPA eGRID grid-mix factor), natural gas heating (therms × EPA 5.31 kg/therm), gasoline driving (miles / MPG × EPA 8.887 kg/gal), flights (DEFRA-published per-flight factors that include radiative-forcing multiplier for high-altitude NOx), and diet (Our World in Data + EAT-Lancet 2024 per-capita diet-class averages). This bottoms-up estimate captures 70-80% of the typical US household's emissions; the remainder is harder-to-attribute consumption (clothing, electronics, services), which footprint calculators usually estimate from income spend. The US per-capita average is ~14 tCO₂e/yr (EPA 2022), versus a global average of ~5 and the IPCC 1.5°C 2050 target of ~2 tCO₂e/capita. The biggest single levers for most US households are flights, beef consumption, and switching electricity to a low-carbon grid mix (or installing solar).