Carbon Footprint Calculator
Calculate your personal annual carbon footprint in pounds of CO₂ from electricity, natural gas, driving, and air travel. Use it to identify your highest-impact emission sources and prioritize reductions.
About this calculator
Your carbon footprint is the total greenhouse gas emissions caused by your activities, expressed in pounds of CO₂ equivalent. This calculator combines four major sources using emission factors established by the U.S. EPA: Annual CO₂ (lbs) = (electricity × 12 × 0.92) + (gasUsage × 12 × 11.7) + ((milesDriven / fuelEfficiency) × 19.6) + (flights × 90). Electricity is multiplied by 0.92 lbs CO₂ per kWh (U.S. average grid intensity). Natural gas uses 11.7 lbs CO₂ per therm. Driving emissions are calculated by dividing annual miles by fuel efficiency to get gallons burned, then multiplying by 19.6 lbs CO₂ per gallon of gasoline. Flight hours are multiplied by 90 lbs CO₂ per hour, a reasonable average for commercial aviation at altitude including radiative forcing effects.
How to use
Inputs: 900 kWh/month electricity, 4 therms/month gas, 12,000 miles/year driving at 30 mpg, and 10 flight hours/year. Step 1 — electricity: 900 × 12 × 0.92 = 9,936 lbs. Step 2 — gas: 4 × 12 × 11.7 = 561.6 lbs. Step 3 — driving: (12,000 / 30) × 19.6 = 400 × 19.6 = 7,840 lbs. Step 4 — flights: 10 × 90 = 900 lbs. Step 5 — total: 9,936 + 561.6 + 7,840 + 900 = 19,237.6 lbs CO₂ per year, or about 8.7 metric tons — close to the U.S. per-capita average.
Frequently asked questions
What is the average carbon footprint per person in the United States?
The average American generates approximately 16 metric tons (about 35,000 lbs) of CO₂ equivalent per year when all consumption categories are included — energy, transportation, food, goods, and services. Energy use and personal vehicle travel alone typically account for 8–12 metric tons for a typical household. The global average is closer to 4 metric tons per person, and climate scientists generally suggest individuals in wealthy nations need to reach 2–3 metric tons by 2050 to meet Paris Agreement targets.
How can I reduce the driving component of my carbon footprint most effectively?
The most impactful step is improving fuel efficiency — switching from a 20 mpg vehicle to a 40 mpg hybrid cuts driving emissions in half without changing how much you drive. Transitioning to a battery-electric vehicle powered by renewable electricity can reduce per-mile emissions by 70–90% compared to a gasoline car. Reducing annual miles through carpooling, remote work, or combining errands also lowers emissions linearly: every 1,000 fewer miles at 25 mpg eliminates about 784 lbs of CO₂.
Why does the calculator use flight hours instead of number of flights?
Flight duration is a better proxy for emissions than flight count because a 1-hour regional hop produces far less CO₂ than a 10-hour transatlantic flight. Using flight hours multiplied by an average emissions rate per hour (here 90 lbs/hour) gives a reasonably accurate estimate across different route lengths. For a more precise figure, dedicated flight carbon calculators use great-circle distance, aircraft type, seat class, and load factor — but the hours-based approach is a practical approximation for a general footprint audit.