Calculate how much food waste is landfilled, the methane it generates, fugitive methane emitted after landfill controls, and methane avoided by diversion. Results are labeled as first-year or cumulative over the selected model period and are designed for households, food businesses, schools, local governments, and program planners.
Food is about 24% of disposed municipal waste in the United States but EPA estimates it causes approximately 58% of fugitive landfill methane because it decays quickly, often before gas collection is installed. This browser-based tool provides a fast, transparent estimate; your entries stay on this device.
Start with five familiar inputs. EPA-aligned assumptions are already loaded.
Changing a preset fills the assumptions above. Selecting Custom site leaves every value editable. Presets are planning defaults, not claims about a particular landfill.
The default mode is aligned with the assumptions published for EPA's Avoided Landfilled Food Waste Methane Emissions Calculator and 2023 research report. It is an independent browser implementation, not the official EPA spreadsheet.
Landfilled mass = annual food waste × landfill share
EPA-aligned CH4 generated in year y = mass × L₀ × methane density × [e^(−k(y−1)) − e^(−ky)]
Collected = generated × age-specific collection efficiency
Emitted = uncollected × (1 − oxidation) + collected × (1 − destruction efficiency)
Avoided landfill CH4 = current emitted − proposed emitted; CO2e = emitted CH4 × selected GWP
IPCC commitment CH4 = mass × DOC × DOCf × MCF × F × 16/12
IPCC methane commitment estimates ultimate methane from a waste deposit with a carbon mass balance; this tool's alternative applies one recovery rate and uses first-order decay only to distribute that commitment over time. First-order decay represents generation as a declining time series controlled by k. LandGEM is EPA's landfill-wide first-order model for repeated annual deposits and several pollutants. WARM is a life-cycle comparison model; its landfill factors include collection timing and other management assumptions. The default here borrows the EPA food-waste k, L₀, and WARM collection schedule but stops at landfill methane.
| Symbol | Plain-language definition | Unit | Default | Accepted range | Source | Effect |
|---|---|---|---|---|---|---|
| k | Food-waste decay rate | year−1 | 0.19 | 0.01–1 | EPA 2023 report, Table 1; WARM v15 | Higher values move methane earlier, often before collection. |
| L₀ | Methane generation potential | m³ CH4/Mg food | 109 | 1–300 | EPA 2023 report, methodology | Scales generated methane directly. |
| ρ | Methane density at 20°C and 1 atmosphere | kg/m³ | 0.667 | Fixed conversion | EPA LandGEM documentation | Converts methane volume to mass. |
| CEy | Collection efficiency by waste age | % | 0, 50, 75, 82.5, 90 | 0–100 | EPA 2023 report, Table 2; WARM v15 | Higher/earlier collection lowers emissions. |
| DE | Flare or energy-device destruction efficiency | % collected CH4 | 99 | 0–100 | EPA 2023 report, BACT assumption | Higher destruction lowers collected-gas slip. |
| OX | Oxidation in landfill cover | % uncollected CH4 | 25 | 0–35 | EPA 2023 report, methane oxidized section | Higher oxidation lowers fugitive methane. |
| GWP | Warming impact per mass CH4 | kg CO2e/kg CH4 | 27.0 | 1–150 | IPCC AR6 WGI, Table 7.15 | Changes CO2e, not methane mass. |
| DOC | Degradable organic carbon | % wet mass | 15 | 0–100 | IPCC 2006 Volume 5, Table 2.4 | Higher DOC raises IPCC-mode generation. |
| DOCf | Fraction of DOC decomposed | % DOC | 50 | 0–100 | IPCC 2006 Volume 5 | Higher DOCf raises IPCC-mode generation. |
| MCF | Methane correction for disposal-site management | ratio | 1.0 | 0–1 | IPCC 2006 Volume 5, Table 3.1 | Lower anaerobic conditions reduce generation. |
| F | Methane fraction of landfill gas | % | 50 | 0–100 | IPCC 2006 Volume 5 | Higher F raises methane generation. |
Each example uses k = 0.19/year, L₀ = 109 m³/Mg, 0/50/75/82.5/90% collection by age, 99% destruction, 25% oxidation, a 30-year period, LandGEM methane density 0.667 kg/m³, and AR6 non-fossil methane GWP100 = 27.0.
Inputs: 10 lb/week × 52 = 520 lb/year (235.87 kg); current landfill 100%; proposed landfill 25%.
Generated = 0.23587 Mg × 109 m³/Mg × 0.667 kg/m³ × (1 − e^(−0.19×30)) = 17.09 kg CH4
Across the current scenario, 4.00 kg is collected (3.96 kg destroyed), 3.27 kg is oxidized, and 9.86 kg CH4 is emitted = 266.10 kg CO2e. Reducing landfill share to 25% avoids 7.39 kg CH4 (199.57 kg CO2e) over 30 years.
Inputs: 1 short ton/month × 12 = 12 short tons/year (10.886 Mg); current landfill 100%; proposed landfill 50%.
Generated = 10.886 Mg × 109 × 0.667 × (1 − e^(−0.19×30)) = 788.81 kg CH4
Across the current scenario, 184.79 kg is collected (182.94 kg destroyed), 151.01 kg is oxidized, and 454.87 kg CH4 is emitted = 12.28 metric tonnes CO2e. Diverting half avoids 227.43 kg CH4 (6.14 t CO2e) over 30 years.
Inputs: 1,000 short tons/year generated; current landfill 100%; 400 short tons diverted, leaving 60% landfilled.
Generated = 907.185 Mg × 109 × 0.667 × (1 − e^(−0.19×30)) = 65.73 metric tonnes CH4
Across the current scenario, 15.40 t is collected (15.25 t destroyed), 12.58 t is oxidized, and 37.91 t CH4 is emitted = 1,023.45 t CO2e. Diverting 400 tons avoids 15.16 t CH4 (409.38 t CO2e) over 30 years.
Verification note: equations and worked examples were independently recalculated in code. The result display includes EPA's national reference of about 34 metric tonnes fugitive CH4 per 1,000 US short tons as a cross-check; a custom-site result is not expected to match that national study exactly.
| Default or claim | Exact source and location | Version used |
|---|---|---|
| 24% disposed waste; 58% fugitive methane; 34 t CH4/1,000 short tons | EPA-600-R-23-064, Executive Summary and Results | October 2023 |
| k = 0.19/year; L₀ = 109 m³/Mg | EPA-600-R-23-064, Table 1 and Methane Generation section | WARM v15 basis |
| Methane density = 0.667 kg/m³ at 20°C and 1 atmosphere | EPA landfill direct-emissions / LandGEM documentation | EPA conversion basis |
| Collection 0/50/75/82.5/90%; destruction 99% | EPA-600-R-23-064, Table 2 and Landfill Gas Combustion section | WARM v15 basis |
| Oxidation 25%; modeled range 0–35% | EPA-600-R-23-064, Methane Oxidized section | October 2023 |
| Official avoided-emissions calculator context | EPA calculator download and description | Spreadsheet dated 30 December 2024 |
| DOC, DOCf, MCF, F | IPCC 2006 Guidelines, Volume 5, Chapters 2–3 | 2006 Guidelines |
| AR6 methane GWP choices | IPCC AR6 WGI Chapter 7, Table 7.15 | AR6 (2021) |
v2.0 — 18 July 2026: added EPA-aligned yearly decay and collection, retained IPCC alternative, simplified inputs, added scenario-by-tonnage planning, accessible results, sensitivity ranges, benchmarks, worked examples, synchronized FAQ/HowTo data, and explicit calculation boundaries.
Using EPA's L₀ of 109 m³ methane per metric tonne and LandGEM's methane density of 0.667 kg/m³, one metric tonne has a modeled methane-generation potential of about 73 kg CH4 before collection, destruction, and oxidation. EPA's national study estimated 34 metric tonnes of fugitive CH4 per 1,000 US short tons, equal to about 34 kg per US short ton, over 30 years.
A landfill buries wet organic material in oxygen-poor conditions where methane-forming microbes thrive. Well-managed compost is kept aerobic, so carbon is emitted mainly as biogenic carbon dioxide; poor aeration can still create methane pockets. This calculator does not calculate composting emissions.
EPA WARM v15 uses k = 0.19 per year for food waste, equivalent to a 3.6-year half-life. About half of its modeled methane potential is generated within that time, so much can form before gas collection reaches high efficiency.
No. EPA's phased WARM schedule assumes no collection in years 0–4, then 50%, 75%, 82.5%, and finally 90% collection. Collected gas is typically destroyed efficiently, but early and uncollected methane can escape or be oxidized in cover soil.
Recovery or collection is methane drawn into a landfill gas system; destruction is the collected share combusted in a flare or energy device. Oxidation is the uncollected methane converted largely to carbon dioxide by microbes in cover soil before it reaches the atmosphere.
Use the value required by your reporting framework. The AR6 non-fossil methane choices here are GWP100 27.0 and GWP20 79.7. Legacy WARM compatibility uses 25. GWP changes CO2e only, not kilograms of methane.
EPA WARM compares life-cycle emissions across waste-management pathways and includes factors outside this tool's boundary. This calculator's EPA-aligned mode applies published food-waste decay, methane potential, phased collection, destruction, and oxidation assumptions only to avoided landfill methane; it is not the official EPA spreadsheet.
The estimate can support screening, program planning, and a documented grant assumption, but it is not a regulatory inventory or verification. Formal reporting should use the required protocol, disposal history, measured gas recovery, site-specific cover data, and qualified review.
A landfill inventory models many years and waste types and may use measured gas flow, local climate, operational history, regulatory equations, and different oxidation or GWP values. This tool models the selected food-waste deposit and diversion scenario with transparent planning assumptions.