Before building our carbon footprint calculator, we looked at reviews and comparisons of existing carbon calculators — and found a consistent complaint.
Personal carbon footprint calculator results don't match each other
Reviews comparing multiple carbon calculators found their results simply aren't consistent with each other — some don't even account for basics like the number of people in a household. The underlying reason is usually invisible to the person using the tool: every calculator assumes its own emission factors, especially for electricity, which varies enormously depending on a region's energy grid mix. Two calculators can both be "correct" under their own assumptions and still disagree by a lot.
Showing the numbers instead of hiding them
Rather than trying to out-precision every other calculator, ours does the opposite — it uses just 3 categories (driving, electricity, flights) and states its emission factors directly in the results: 8.887 kg CO2 per US gallon of gasoline (EPA), roughly 0.4 kg CO2 per kWh for US grid electricity, and commonly-cited per-passenger flight averages. If your number looks different from another tool's, you can see exactly why.
CO2 emissions calculator for flights, driving, and electricity
It's intentionally not exhaustive — no questions about diet, home heating type, or shopping habits. Reviews of more thorough calculators note they can be genuinely confusing to fill out and easy to get lost in. This one takes under a minute.
