Home and Office Energy Usage
We calculate emissions from electricity generation with the EPA’s eGRID emission factors based on 2018 data published in 2020, using the US average electricity source emissions of 0.947 lbs CO2e per kWh (0.429 kgs CO2e per kWh).
There are 10.16 kgs of CO2e per gallon of home heating oil. (Source: U.S. Department of Energy)
There are 0.00531 metric tonnes of CO2e per 100 cubic feet (CCF) of natural gas. (Source: U.S. Department of Energy)
There are 0.00576 metric tonnes of CO2e per gallon of propane. (Source: U.S. Department of Energy)
Unleaded automobile gasoline emits 8.78 kgs CO2e per gallon. Diesel fuel emits 10.21 kgs CO2e per gallon.
CO2 emissions for coach/economy air travel vary by length of flight, ranging from 0.134 kgs CO2e per passenger mile to 0.217 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.
The CO2e emissions for long distance trains (i.e., intercity rail) is 0.114 kgs per passenger mile.
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 0.209 kgs/ton-mile
Air shipping emissions factor is 1.278 kgs/ton-mile
Rail shipping emissions factor is 0.021 kgs/ton-mile
Ocean/water shipping emissions factor is 0.0409 kgs/ton-mile
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.
Our 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 – 1.278 kg CO2e per Tonne-Mile
- Truck – 0.209 kg CO2e per Tonne-Mile
- Train – 0.021 kg CO2e per Tonne-Mile
- Sea freight – 0.0409 kg CO2e per Tonne-Mile
(Source: EPA Emissions Factors for Greenhouse Gases Inventories 2020)
- 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
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
All travel emissions factors sourced from EPA Emissions Factors for Greenhouse Gases Inventories 2020.
- Short flights are calculated to be under 300 miles one-way with emissions of 0.217kg CO2e per passenger mile
- Medium flights are calculated to be 300-2300 miles one-way, average 1500 miles, with emissions of 0.134 kg CO2e per passenger mile
- Long flights are calculated to be > 2300 miles, average 3,000 miles one-way with emissions of 0.167kg CO2e per passenger mile
- Train trips are calculated 0.114 kg CO2e per passenger mile
- Subway trips are calculated 0.1 kg CO2e per passenger mile
- Bus trips are calculated at 0.056 kg CO2e per passenger mile
All emissions figures from EPA Emissions Factors for Greenhouse Gases Inventories 2020.
- Commute by Car – assumes 0.338 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 0.114 kg CO2e emitted per mile.
- Commuter Rail – Assomes a two way commute 245 days a year, with 0.149 kg of CO2e emitted per mile.
- Commute by Transit (tram, subway) – assumes a two way commute 245 days a year, with 0.1 kg of CO2e emitted per mile.