Assumptions and References for Household Carbon Footprint Calculator

Your Current Household Emissions Sources

Household Vehicles

Pounds of carbon dioxide equivalent are calculated based on estimates of the typical values for fuel economy and miles driven per week from the Federal Highway Administration's Highway Statistics 2022 Table VM-1, and pounds of CO₂ emitted per gallon of gasoline from and the U.S. Energy Information Administration’s “Carbon Dioxide Emissions Coefficients by Fuel" data (2022). Calculations for the ratio of total emissions to CO₂-only emissions are from the EPA (2024) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022. U.S. Environmental Protection Agency, EPA 430-R-24-004. Chapter 3 (Energy), Tables 3-13, 3-14, and 3-15. Note that EPA's emissions estimates are lower than estimates obtained through fueleconomy.gov, because EPA's estimates are for tailpipe emissions only. The fueleconomy.gov site estimates emissions over the full fuel lifecycle (including extraction, processing, and transportation of fuel).

Electricity

Electricity emissions factors are categorized by geographic subregion. Source: EPA eGRID Summary Tables 2022, Table 1, published January 30, 2024.

"Typical" annual CO2e emissions are 8744 pounds per household, assuming approximately 881 kWh per month. Source: U.S. Energy Information Administration 2024. Residential Energy Consumption Survey 2020 Fuel Consumption in the U.S. Table CE2.1 (pdf). Calculated using emission factor from EPA eGRID Summary Tables 2022, Table 1, published January 30, 2024.

Natural Gas

Carbon coefficient for natural gas: 117 pounds of CO₂ per million BTU, or 0.12 pounds per cubic foot of gas. Source: EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022, Annex 2, Table A-29 Carbon Content Coefficients for Natural Gas (2024).

"Typical" annual CO₂ emissions of 6,853 pounds per household based on national average monthly consumption of 4,717 cubic feet of gas. Source: U.S. Energy Information Administration Residential Energy Consumption Survey 2020 Fuel Consumption in the U.S. Table CE2.1 (pdf).

Fuel Oil

Carbon coefficient for distillate fuel (fuel oil): 163 pounds of CO₂ per million BTU, or 22.46 pounds per gallon. Source: U.S. EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022, Annex 2,Table A-30 Carbon Content Coefficients and Underlying Data for Petroleum Products, Distillate fuel oil no. 2. (EPA 2024).

"Typical" annual CO₂ emissions of 11,386 pounds per household based on national average monthly consumption of 42 gallons of oil. Source: U.S Energy Information Administration 2020. A Look at Residential Energy Consumption in 2020 Table CE2.1.

Propane

Carbon coefficient for LPG (propane): 139 pounds of CO₂ per million BTU, or 12.68 pounds per gallon. Source: U.S. EPA I Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022, Annex 2, Table A-30 Carbon Content Coefficients and Underlying Data for Petroleum Products, LPG (Propane). (EPA 2024).

"Typical" annual CO₂ emissions of 4,906 pounds per household based on national average monthly consumption of 32 gallons of propane. Source: U.S Energy Information Administration 2020. A Look at Residential Energy Consumption in 2020 Table CE2.1.

Waste Disposal

Estimates of greenhouse gas emission benefits from recycling newspaper, glass, plastic, metal, and magazines were developed using national waste data and life-cycle greenhouse gas emission factors for waste management. Calculations assume that it would be possible for households to recycle 100 percent of all recyclable materials generated as waste. For example, if you indicate that you recycle newspapers, this calculator assumes that you recycle 100 percent of the newspapers you receive. It is estimated that on average, each person generates 0.015 tons of newspaper, 0.029 tons of glass, 0.035 tons of plastic, 0.012 tons of metal, and 0.003 tons of magazines per year.

Source: EPA, Documentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM) 16, Containers, Packaging, and Non-Durable Good Materials Chapters, (Dec 2023). Per capita recycling figures derived from total waste generated divided by rounded 2022 population of 33,000,000.

Carbon dioxide equivalent emissions associated with household waste management were calculated using the total emissions for landfills (including incineration, landfill gas-to-energy projects, oxidation, and flaring) from EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2022. The emission factors for each material type were developed by EPA and presented in the Agency's report on greenhouse gas emissions from waste management and in the online Waste Reduction Model (WARM). These emission factors take into account the full material life cycle; i.e., not only emissions at the landfill, but also emissions and sequestration associated with production, manufacturing, remanufacturing, forest carbon storage due to reduced harvests, etc. The emission factor used for recycling materials in this calculator compares greenhouse gas emissions from recycling with those attributable to landfilling. This approach enables policy makers to evaluate, on a per-ton basis, the overall difference in greenhouse gas emissions between (1) recycling 1 ton of material and (2) manufacturing and then managing (post-consumer) 1 ton of the same material. Source: U.S. Environmental Protection Agency, 2023. Waste-Reduction Model (WARM) Version 16.

What You Can Do to Reduce Your Emissions

On the Road

Emission factors based on EPA's estimate of the average annual emissions and fuel consumption for gasoline-fueled passenger cars and light trucks in the United States.

Cost savings for reducing the number of miles driven are calculated using 18 cents per mile (includes gas, oil and maintenance). Source: Transportation Energy Data Book, Table 11.15 Car Operating Cost per Mile, 1985-2020, Variable Cost, (2022).

Properly inflating tires: Assumes an average increase in fuel efficiency of 0.6 percent. Using the recommended grade of motor oil: Assumes an increase in fuel efficiency of 1-2 percent.

Overall increase in fuel efficiency from performing regular maintenance on your vehicles: 1.6%

Source: Environmental Protection Agency and Department of Energy, Fuel Economy Website, 2024

Perform regular maintenance on your vehicles: Assumes an increase in fuel efficiency of 7 percent. Source: Environmental Protection Agency and Department of Energy, Fuel Economy Website, 2011.

Cost savings for purchasing a more fuel efficient vehicle are calculated using $3.69 per gallon. Source: Energy Information Administration (EIA), 2023. Annual average price per gallon of gasoline (all grades).

At Home

Cost savings for natural gas consuming devices assume an average cost of $15.23 per thousand cubic feet. Source: Energy Information Administration: Natural Gas Prices, Residential Price (2024).

Cost savings for electricity consuming devices assume average cost per kWh of $0.1609. Source: U.S. Energy Information Administration, Electric Power Monthly - October 2021, Table 5.3 (Average Retail Price of Electricity to Ultimate Customers, Residential Sector), 2024 Rolling 12 Months Ending in April.

Cost savings for fuel oil consuming devices assume an average cost of $4.27 per gallon. Source: Energy Information Administration, April 2020. US No. 2 Heating Oil Residential Prices - 2019 annual average.

Cost savings for propane consuming devices assume an average cost of $2.56 per gallon. Source: Energy Information Administration, U.S. Propane Residential Price - 2023 annual average. (2024).

Turning down your heating thermostat: Assumes 3 percent savings in heating energy use for a 1 degree decrease. Source: ENERGY STAR. Life Cycle Cost Estimating Tool for ENERGY STAR Programmable Thermostats, 2008. Assumes that, nationally, 9% of annual residential electricity consumption, 63% of annual natural gas consumption, 70% of annual propane consumption, and 87% of annual fuel oil consumption are used for space heating. Source: Energy Information Administration. A Look at Residential Energy Consumption in 2009,Table CE4.1

Turning up thermostat for central air conditioner: Assumes 6 percent savings in cooling energy use for a 1 degree increase. Source: ENERGY STAR. Life Cycle Cost Estimating Tool for ENERGY STAR Programmable Thermostats, 2008. Assumes that nationally, 14% of annual electricity consumption is used for space cooling. Source: U.S. Energy Information Administration. End-use Consumption of Electricity. Energy Information Administration. A Look at Residential Energy Consumption in 2009,Table CE4.1

Enable sleep feature on your computer and monitor. Assumes ENERGY STAR desktop computer and monitor. Average annual unit computer energy (sleep feature enabled, computer turned off at night): 71 kWh; average annual unit computer energy (sleep feature not enabled, computer turned off at night): 143 kWh. Average annual unit monitor energy (sleep feature enabled, monitor turned off at night): 32 kWh; average annual unit monitor energy (sleep feature not enabled, monitor turned off at night): 67 kWh. Source: ENERGY STAR Data Book Worksheet for 2014.

Wash clothes in cold water instead of hot: Assumes average use of 289 kWh per year or 0.96 kWh per load. Source: ENERGY STAR Data Book Worksheet for 2014. Use a clothes line or drying rack for 50% of your laundry, instead of your dryer: Assumes 769 kWh of electricity used per year. Source: U.S. Department of Energy Office of Energy Efficiency & Renewable Energy, Amended federal standard (10 CFR 430.32(h)(3)) for residential clothes dryers.

Assumes 43 watt halogen light bulb (unit energy consumption: 47 kWh/year) is replaced with with a 9 watt LED bulb (unit energy consumption: 10 kWh/year). Assumes light is on for 3 hours per day. Source: ENERGY STAR data book 2024, Annual & Lifetime Savings from ENERGY STAR Certified Products, Residential and Commercial Lighting, Light Bulbs (halogen vs. LED).

Replacing old refrigerator with an ENERGY STAR model: Assumes old model uses 617 kWh per year; ENERGY STAR model uses 488 kWh per year. Source: 2024 ENERGY STAR Data Book, Annual & Lifetime Savings from ENERGY STAR Certified Products, 2010 refrigerator energy consumption from ENERGY STAR Databook 2020, table: Historical Appliance Energy and Water Usage Table with a degredation factor applied.

Replacing an old boiler or furnace with an ENERGY STAR model: Assumes 2000 sq ft house; 300 square feet of glass. Source: 2024 ENERGY STAR Data Book, Annual & Lifetime Savings from ENERGY STAR Certified Products.

Replacing single-pane windows with ENERGY STAR windows: Assumes 2000 square-foot house, 300 square feet of glass. Source: ENERGY STAR. Methodology based on RESFEN 3.1 calculations performed by Lawrence Berkeley National Laboratory (LBNL), 2005. Average annual energy cost savings from changing to ENERGY STAR windows from 2024 ENERGY STAR Data Book, Figure on average savings when replacing windows by region.

Recycling

Calculations assume that it would be possible for households to recycle 100 percent of all recyclable materials generated as waste. The plastic material type used in the calculator includes PET and HDPE, and the metal material type includes aluminum and steel cans.