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Calculation Methods

Home and Office Energy Usage

We calculate emissions from electricity generation with the EPA’s eGRID emission factors data published in 2025, using the US average electricity source emissions of 0.7715 lbs CO2e per kWh (0.3499 kgs CO2e per kWh).

There are 22.45 pounds of CO2e per gallon of home heating oil. Source: U.S. Department of Energy

There are 12.085 pounds of CO2e per 100 cubic feet (CCF) of natural gas. Source: U.S. Department of Energy

There are 12.68 pounds of CO2e per gallon of propane. Source: U.S. Department of Energy

Travel

Unleaded automobile gasoline emits 20.86 pounds CO2e per gallon. Diesel fuel emits 22.45 pounds CO2e per gallon. Source: U.S. Department of Energy

CO2 emissions for coach/economy air travel vary by length of flight, ranging from 0.129 kgs CO2e per passenger mile to 0.207 kgs CO2e per passenger mile, with higher emissions for shorter flight segments. Our calculator uses a simplified factor of 0.2 kgs per passenger mile. Source: Emission Factors for Greenhouse Gas Inventories (epa.gov)

The CO2e emissions for long distance trains (i.e., intercity rail) is 0.293 pounds per passenger mile. Source: EPA – Emission Factors for Greenhouse Gas Inventories

Product shipping emissions is calculated by the total number of parcels multiplied by the average parcel weight and average parcel shipping distance then by the applicable emissions factor per ton-mile.

Ground/truck shipping emissions factor is 0.41 pounds/ton-mile
Air shipping emissions factor is 2.394 pounds/ton-mile
Rail shipping emissions factor is 0.046 pounds/ton-mile
Ocean/water shipping emissions factor is 0.17 pounds/ton-mile

Source: EPA – Emission Factors for Greenhouse Gas Inventories

 

 

Total US CO2-Equivalent Emissions

In 2019, US greenhouse gas emissions totaled 5.77 billion metric tonnes CO2-equivalent (published 2021). That figure is divided by the estimated US population according to the 2020 US Census results to yield CO2-equivalent per person. (Source: US Environmental Protection Agency/US Census Bureau) We’ve rounded up a US-based individual’s annual carbon footprint to 24 metric tonnes (about 50,000 pounds) to account for non-US based emissions from activities such as international travel and international purchases/product shipments.

Hospitality

A mixed-menu (meat and vegetables) at an average event will yield around 4 pounds of CO2e per person per meal. Source: TableDebates.org

Emissions associated with a one-night stay in a hotel room are calculated at 21.605 lbs CO2e per room day for an average US-based hotel. Source: Environmental Protection Agency, CHP Potential in the Hotel and Casino Market Sectors, prepared by Energy and Environmental Analysis, Inc. for EPA.

We are using a venue events emission factor of 0.769 pounds CO2e per person per day. Source: US Energy Information Administration 

Water consumption estimates vary. The industry average is around 200 gallons/room-night, assuming there is in house laundry service and restaurant facilities. Source – SPU.

Water consumption estimates vary. Event estimates are around 80 gallons per attendee. Source: USGS.

Shipping Calculator

ClimeCo’s shipping calculator utilizes three user generated inputs to determine a unit called a ‘tonne-mile’ (e.g. a tonne of freight traveling 1 mile, or a half tonne of freight traveling two miles, or 1/1000th of a tonne traveling 1,000 miles… you get the point):

  • Total number of shipments
  • Avg Weight of Shipment (lbs)
  • Avg Shipping Distance (mi)

Shipping Emissions Factors

  • Air cargo – 2.394 pounds CO2e per Ton-Mile
  • Truck – 0.41 pounds CO2e per Ton-Mile
  • Train – 0.046 pounds CO2e per Ton-Mile
  • Sea freight – 0.17 pounds CO2e per Ton-Mile

Source: EPA – Emission Factors for Greenhouse Gas Inventories

Conversions

  • 1 Renewable Energy Certificate = 1 Megawatt Hour (MWh) = 1,000 Kilowatt Hours (KWh)
  • 1 Kilowatt Hour = 3,413 British Thermal Units (BTUs)
  • 1 Metric Tonne = 2,204.6 Pounds
  • 1 Pound = 0.00045 Metric Tonnes
  • 1 Short Ton = 2,000 Pounds
  • 1 Short Ton = 0.90719 Metric Tonnes
  • 1 Therm = 96.5 Cubic Feet
  • 1 CCF = Abbreviation for 100 Cubic Feet
  • 1 CCF = 1.037 Therms

https://www.eia.gov/tools/faqs/index.php

Business Calculator

All emissions factors in the “Office Emissions” category are based on annual (12 month) emissions. Emissions factors for energy (kWh) are based on state-based figures from the EPA eGRID

There are 12.085 pounds of CO2 per 100 cubic feet (CCF) of natural gas. Source: U.S. Department of Energy

Emissions factors for electricity by your monthly bill are based on state based figures from the EPA eGRID to get the state-by-state prices for energy, and the emissions factors are generated from the Department of Energy’s Energy Information Administration. On average across the US, electricity sources emit 0.7715 lbs CO2 per kWh. State CO2 emissions per kWh may vary greatly in accordance with the amount of clean energy in the energy supply.

There are 22.45 pounds of CO2 per gallon of home heating oil (diesel fuel). Source: U.S. Department of Energy

There are 12.68 pounds of CO2 per gallon of propane. Source: U.S. Department of Energy

Server emissions are calculated assuming an average 251 watt server (source: Vertatique) with 95% up time. The energy usage of each server is then multiplied by state based emissions factors.

Fleet emission calculations assume the national average of 25.2 mpg and the emissions factor of 19.37 lbs CO2 per gallon of gasoline consumed. Fleet emissions for delivery vans and trucks assume an average of 18.8 mpg. and the emissions factor of 22.45 lbs CO2 per gallon of diesel consumed. Fleet emissions big rigs assume an average of 5.4 mpg and the emissions factor of 22.45 lbs CO2 per gallon of diesel consumed. Source: U.S. Department of Energy

All travel emissions factors sourced from EPA Emissions Factors for Greenhouse Gases Inventories 2025.

  • Short flights are calculated to be under 300 miles one-way with emissions of 0.207 kg CO2e per passenger mile
  • Medium flights are calculated to be 300-2300 miles one-way, average 1500 miles, with emissions of 0.129 kg CO2e per passenger mile
  • Long flights are calculated to be > 2300 miles, average 3,000 miles one-way with emissions of 0.163 kg CO2e per passenger mile
  • Train trips are calculated 0.133 kg CO2e per passenger mile
  • Subway trips are calculated 0.096 kg CO2e per passenger mile
  • Bus trips are calculated at 0.066 kg CO2e per passenger mile

All emissions figures from EPA Emissions Factors for Greenhouse Gases Inventories 2025

  • Commute by Car – assumes 0.297 kg CO2e of gas consumed per mile and a two way commute 245 days a year. (The kg CO2/vehicle mile average of both passenger car and light-duty truck.)
  • Commute by Intercity Rail (Amtrak) – assumes a two way commute 245 days a year, with 0.096 kg CO2e emitted per mile.
  • Commuter Rail – Assumes a two way commute 245 days a year, with 0.133 kg of CO2e emitted per mile.
  • Commute by Transit (tram, subway) – assumes a two way commute 245 days a year, with 0.093 kg of CO2e emitted per mile.

Plastic Usage

Plastic usage data can vary widely depending on methods and materials used. Our 10 grams per item shipped is based on estimates for shipping boxes and plastic tape. Source: EPA

Daily plastic use ranges from 10 grams to more than 400 grams, depending on location. We use a simplified average of 200g to account for different locations. Source: American Association for the Advancement of Science