The composting benefits calculator shows how much CO2e you avoid by diverting food waste from landfill to compost. When food rots in landfill it produces methane — a greenhouse gas 28× more potent than CO2 — making composting one of the most impactful household actions.
Your Composting Habits
Estimates based on EPA methane emission factors for landfilled food waste. Actual values vary.
How to Calculate Composting Benefits
Enter the amount of food scraps and yard waste you compost weekly. The calculator estimates annual CO2e savings from avoided landfill methane, total waste diverted, and usable compost produced.
Why Methane Matters
Food in landfill decomposes without oxygen, producing methane gas. Methane is 28× more potent than CO2 as a greenhouse gas over 100 years. The EPA estimates that food waste in landfills produces the greenhouse gas equivalent of 58 million cars annually in the US alone. Composting converts this methane-producing pathway into aerobic decomposition that produces CO2 instead.
Maximizing Compost Value
Using finished compost in your garden replaces synthetic fertilizers, which require significant energy to produce (about 1.5 kg CO2e per kg of nitrogen fertilizer). A household compost pile producing 50-100 lbs of finished compost per year replaces $15-30 of fertilizer while improving soil health.
Frequently Asked Questions
Is this composting calculator free?
Yes, completely free with no account required.
Why does composting reduce greenhouse gas emissions?
When food waste goes to landfill, it decomposes anaerobically (without oxygen), producing methane — a greenhouse gas 28× more potent than CO2 over 100 years. Composting is an aerobic process that produces CO2 instead of methane, and much of the carbon is sequestered in soil. Landfill food waste is responsible for about 8% of global greenhouse gas emissions.
How much CO2 does composting save per kg of food waste?
Diverting 1 kg of food waste from landfill to compost saves approximately 0.5-0.7 kg CO2e. This is from avoided methane production (the dominant factor) plus the value of the compost replacing synthetic fertilizers. A household composting 3 kg/week saves roughly 100 kg CO2e per year.
What can and cannot be composted?
Compostable: fruit and vegetable scraps, coffee grounds, tea bags, eggshells, grass clippings, leaves, paper and cardboard. Not compostable (in home compost): meat, fish, dairy, oils, diseased plants, pet waste. Industrial composting facilities can handle meat and dairy; check if your area has one.
Does this support metric and imperial?
Yes. Toggle between kg and lbs for waste weight inputs. Results show CO2e savings in both units.