What does this composting impact calculator estimate?

It estimates the CO2e savings from composting food scraps and yard waste that would otherwise be landfilled. Savings are landfill methane avoided minus compost process emissions, plus any optional compost carbon credit you enter.

Does composting have greenhouse gas emissions?

Yes. Composting is mostly aerobic, but small anaerobic zones can emit methane and composting can emit nitrous oxide. The calculator includes editable CH4 and N2O emission factors.

Are the default factors exact for my compost pile or facility?

No. Moisture, aeration, feedstock mix, landfill gas capture, climate, and facility management can change results substantially. Replace defaults with local measurements or documented project factors when available.

Is my composting data uploaded?

No. The calculator runs in your browser and does not send your inputs to a server.

Composting Impact Calculator: CO2e Saved from Food Scraps and Yard Waste

Estimate the climate impact of composting organic waste instead of landfilling it. Everything runs locally in your browser.

Last updatedJune 30, 2026

Core methodLandfill CH4 avoided minus compost CH4 and N2O

SourcesIPCC waste guidance and EPA GWP values

PrivacyNo server upload or input tracking

Inputs

Organic waste

Food scraps Yard waste Mass unit Input period

Diverted to compost (%) Scenario label

Landfill baseline

Landfill type preset Methane correction factor, MCF Methane recovery (%) Cover oxidation (%)

Food waste DOC (% wet weight) Yard waste DOC (% wet weight) DOCf (% of DOC decomposes) CH4 fraction in landfill gas (%)

Compost process and reporting

Compost CH4 factor Compost N2O factor Operations/transport

Optional compost carbon credit CH4 GWP100 N2O GWP100 Report scale

Compost CH4 and N2O factors are in grams of gas per kg wet waste treated. Operations and optional carbon credit are kg CO2e per metric tonne of wet waste.

Results

Enter organic waste amounts, then calculate.

What This Calculator Estimates

This tool compares a landfill baseline with a composting scenario for the organic waste you divert. It estimates methane that would have been emitted from landfill disposal, subtracts methane and nitrous oxide from composting, and reports the net CO2e saved.

Diverted waste = annual food scraps and yard waste x composted share Landfill CH4 generated = waste mass x DOC x DOCf x MCF x methane fraction x 16 / 12 Landfill CH4 emitted = (CH4 generated - CH4 recovered) x (1 - oxidation) Compost CO2e = compost CH4 x CH4 GWP + compost N2O x N2O GWP + operations CO2e Net CO2e saved = landfill baseline CO2e - compost CO2e + optional compost carbon credit

The result is a planning estimate for a one-year waste stream. It is not a formal greenhouse gas inventory, compost facility permit model, or certified offset calculation.

Assumptions and Sources

Landfill DOC defaults use IPCC municipal solid waste values: 15% wet weight for food waste and 20% wet weight for garden and park waste.
DOCf defaults to 50%, methane fraction defaults to 50%, and MCF presets follow IPCC solid waste disposal site classes.
Compost process defaults use IPCC wet-weight Tier 1 factors: 4 g CH4/kg waste and 0.24 g N2O/kg waste.
GWP100 defaults use 28 for CH4 and 273 for N2O. EPA summarizes current IPCC AR6 CH4 GWP100 as a 27-30 range and N2O as 273.
The optional compost carbon credit defaults to zero because soil carbon retention depends on compost quality, application rate, soil, climate, and accounting boundary.

References: IPCC 2006 Guidelines Volume 5, Chapter 2, IPCC 2006 Guidelines Volume 5, Chapter 3, IPCC 2006 Guidelines Volume 5, Chapter 4, and EPA Understanding Global Warming Potentials.

FAQs

Why can composting still show emissions?

Composting is aerobic when managed well, but pockets without enough oxygen can produce methane, and nitrogen cycling can produce nitrous oxide. Good aeration, moisture control, and feedstock balance usually reduce those risks.

Why is the landfill methane recovery setting important?

Captured landfill gas reduces emitted methane. If the landfill has high, verified gas capture, the composting savings may be smaller than at an unmanaged or low-capture landfill.

Should I include a compost soil carbon credit?

Only include it when you have a documented factor for your compost use and accounting boundary. The default is zero to avoid overstating savings.

Does this include avoided fertilizer or water savings?

No. It focuses on waste-management greenhouse gases. Compost can affect soil health, fertilizer demand, and moisture retention, but those benefits need site-specific factors.

Can I use this for a business or municipal report?

Use it as a transparent screening estimate. Formal reports should use documented activity data, local landfill and compost facility factors, and the GWP set required by the reporting program.