Enrichment · Passion Projects · Environment

Your bills,
in tons of CO₂.

Type what the electric, gas and fuel bills say and how far you drive. The estimator turns each into carbon dioxide and shows which source matters most.

Estimate our footprintWhat you get

The household carbon footprint estimator

The worked example is a two-person apartment with gas heat and one car. Nothing you type leaves this browser.

Loading the calculator. If nothing appears, turn on JavaScript.

What you get

Enrichment · Passion ProjectsFree

What you finish with
Yearly carbon dioxide from electricity, natural gas, heating oil, propane and gasoline, the total in metric tons and per person, shares by source and the effect of a 10 percent cut. It prints as a summary for a project or a family plan.
Who it is for
Families looking for the biggest change to make, students doing an energy or climate project with their own bills, and adults tracking household energy.
Format
Browser estimator for a phone, tablet or computer, by touch or keyboard. Prints a summary; downloads a spreadsheet (.csv); export and import a file.
Access
Free. No account, no sign-in and nothing to install. Everything you type stays in this browser; nothing is sent to Caveat.
Where it lives
The Passion Projects space in Caveat Enrichment.
Support
Questions, a correction or a request: team@caveatacademic.com.

How to use it

  1. Find a few months of bills.
  2. Type the monthly averages.
  3. Set your region’s grid factor.
  4. Add the miles and mpg.
  5. Start with the largest source.

Estimate our footprint

How the estimate works

Use times an emission factor, source by source.

The worked example: a two-person apartmentElectricity2.90 t7,800 kWh × 0.82 lbNatural gas2.55 t480 therms × 11.7 lbGasoline3.49 t393 gal × 19.6 lbTotal8.9 t4.5 t a personThe worked example: a two-person apartmentElectricity2.90 t7,800 kWh × 0.82 lbNatural gas2.55 t480 therms × 11.7 lbGasoline3.49 t393 gal × 19.6 lbTotal8.9 t4.5 t a person
Each year’s use is multiplied by its emission factor, then pounds are converted to metric tons and added.

Emission factors

Burning a fuel releases a known amount of carbon dioxide: about 19.6 pounds for a gallon of gasoline, 11.7 for a therm of natural gas, 22.4 for a gallon of heating oil and 12.7 for a gallon of propane. Electricity depends on how your region generates it; the U.S. average is near 0.8 pounds a kilowatt-hour, and EPA’s eGRID lists each region.

What it leaves out

This covers fuel and power used at home and in the car. A complete footprint also includes flights, food, goods and services, and other greenhouse gases, which together often add more than home energy does. Use it to compare your own year to year, or one change against another.

Sources

  1. U.S. Environmental Protection Agency. Greenhouse Gas Equivalencies Calculator: calculations and references (epa.gov).
  2. U.S. Environmental Protection Agency. Emissions and Generation Resource Integrated Database (eGRID) (epa.gov/egrid).
  3. U.S. Energy Information Administration. Carbon dioxide emissions coefficients by fuel (eia.gov).
  4. U.S. Environmental Protection Agency. Greenhouse gas emissions from a typical passenger vehicle (epa.gov).

An estimate from average factors; your utility and vehicle may differ. Your entries stay in this browser. Support: team@caveatacademic.com.