How the estimate is built
Each activity you enter is multiplied by an emission factor, which is the average amount of carbon dioxide released per unit of that activity. The four results are added together to give a monthly total, then multiplied by twelve and divided by a thousand to project metric tons per year.
The per-source breakdown lets you see which part of your routine carries the most weight, which is usually where small changes have the biggest payoff.
Reading your result
The headline number is kilograms of CO2 per month; the annual figure restates it in metric tons for easier comparison with national or per-person averages.
- Focus on the largest bar in the breakdown first.
- Compare two scenarios by running it twice with different inputs.
- Use the annual tons figure when comparing against published targets.
Ways to lower the number
Once you know where your emissions concentrate, you can target them directly.
- Cutting flights tends to move the total the most for frequent travelers.
- A cleaner electricity plan or rooftop solar reduces the power component.
- Driving less, carpooling or switching fuel sources trims the gasoline share.
Disclaimer and caveats
This is an estimate only. The emission factors are generic averages and real numbers vary widely by region, electricity grid mix, vehicle efficiency, flight class and the methodology used.
Different calculators will give different totals because they choose different factors and boundaries. Use this figure to understand rough proportions and trends, not as an audited measurement.
Formula
emissions = Σ (activity × emission factor)Frequently asked questions
- How accurate is this?
- It uses generic average emission factors. Your actual footprint depends on your local grid, fuel efficiency and other factors, so treat it as a ballpark figure.