The numbers behind your footprint, savings, and offsets.
Carbon, water, energy, recycling, and food-waste math — quantify your impact, the savings from changing it, and where to focus first.
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Hand-picked starters.
Measure your annual CO₂ footprint.
Driving, flights, diet, and home energy — the four levers that actually move your carbon number.
Carbon Footprint
Drag weekly driving miles, yearly flights, and diet type. The widget computes annual CO₂ vs. the U.S. average.
Flight Carbon Calculator
CO₂ per leg by route, class, and round-trip — plus the equivalent driving miles for the same emissions.
~0.9 tNYC→LAX one-wayWhere a household's footprint actually comes from.
The average American runs ~16 t CO₂e a year. Trace it stream by stream — home, car, flights, food — and open the calculator that prices each piece.
Audit the leaks, then price the panels.
Heating, cooling, and appliances are the single biggest slice for most households — and the one where efficiency upgrades pay back fastest.
The steadiest emitter in the driveway.
Every gallon burned is 8.89 kg of CO₂ — driving style, route choice, and switching the charge source move the number more than most people expect.
One trip can outweigh months of driving.
A single cross-country flight adds nearly a tonne per seat — price the leg, then check what offsetting it would actually cost.
What gets bought, tossed, and run down the drain.
Roughly 30% of purchased food never gets eaten — the cheapest carbon win in the house is wasting less of what's already in the fridge.
When the panels pay themselves off.
Solar ROI, payback periods, battery sizing, EV charging cost, and the home-energy audit that finds the leaks first.
Solar ROI Detailed
Drag system cost, monthly kWh, and sun-hours per day. Annual savings + payback years update live.
Home Energy Audit
Insulation, windows, HVAC, and appliance scores — find the leaks worth fixing first.
~$200/yravg savings from sealing leaksGallons per day, by household behavior.
Household water use, rainwater catchment, and the conservation math that translates short showers into actual savings.
Water Usage
Drag household size, shower minutes, and laundry loads/week. Daily gallons compute live vs. the 82 gal/person U.S. average.
Rainwater Collection
Roof area × annual rainfall × efficiency — gallons of free water you could be capturing.
~12,500 gal/yr1,500 ft² @ 30" rainCO₂ and dollar savings from diverting waste.
Recycling, composting, plastic-footprint, and the circular-economy math behind diverting waste from landfill.
Recycling Savings
Drag weekly recycled volume. CO₂ + dollar value compute live against landfill alternative.
Plastic Footprint
Annual plastic generated by household, broken down by category — bottles, packaging, bags.
~150 lb/yravg US householdThe cost (and carbon) of what gets thrown out.
U.S. households throw out ~30% of the food they buy. Both calculators below quantify the impact in dollars and CO₂.
Food Waste Cost
Drag your weekly grocery spend and how much gets thrown out — the widget shows the dollars and CO₂ you toss each year.
Food Miles Carbon
CO₂ emissions per produce category by transport mode — air freight vs. ocean freight vs. local.
~0.5 kg CO₂per kg of food transportedTwo good options? See the head-to-head.
The environment vocabulary, decoded.
Every definition links to the calculator that puts the term to work. Browse the full glossary →
Driving CO₂ = miles × 8.89 kg/gal ÷ MPGThe EPA tailpipe factor: every gallon of gasoline burned releases 8.89 kg of CO₂, so your annual miles and fuel economy set your driving footprint.Solar payback (yr) = net system cost ÷ annual electricity savingsYears until the panels pay for themselves — net cost is after the federal tax credit and state incentives.Trees to offset = annual CO₂ (kg) ÷ ~22 kg per mature treeA mature tree sequesters roughly 22 kg of CO₂ per year — the conversion behind every tree-planting offset claim.Frequently asked questions
How accurate is the Carbon Footprint calculator?
The widget uses EPA-published emission factors for transportation, electricity, and food. Driving uses an assumed 25 MPG; flights use 0.45 kg CO₂ per passenger-mile; diet ranges from 1.7 t CO₂/yr (vegan) to 3.3 t (meat-heavy). Real-life carbon varies by region, vehicle, and electricity grid — the full calculator surfaces those inputs separately.
What's a "good" Solar ROI payback period?
7–10 years is typical for residential solar in the U.S. with current federal tax credits. Under 7 years signals high-sun states (AZ, NV, CA) or aggressive state incentives. Over 12 years usually means low local electric rates, lots of shading, or a system that's overbuilt for the household's actual use. The full calculator surfaces region-specific incentives.
Why does food carbon vary so much?
Beef is ~60 kg CO₂/kg; lamb ~24 kg; chicken ~9 kg; produce ~0.5–2 kg. The single biggest carbon lever in most U.S. diets is reducing red-meat frequency. The Carbon Footprint widget simplifies this to four diet tiers; the full calculator lets you weight specific food categories.
Should I prioritize recycling or reducing first?
Reducing always beats recycling in carbon terms — a recycled aluminum can still required mining, smelting, transport. Recycling Savings quantifies the carbon already avoided by diversion; Plastic Footprint focuses on the upstream "don't generate it in the first place" lever.
Are tree-planting offsets a real solution?
Trees absorb ~22 kg CO₂/year once mature — so one tree per ~2 years offsets a single transatlantic flight. Offsets work as a supplemental measure but not as a substitute for emission reduction. The Carbon Offset and Tree Planting calculators surface the math both ways: as additive offset and as marginal cost per ton avoided.
11 categories, one search box, zero signups. If it has a number, we calculate it.
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