Cycling CO2 Impact Calculator

Even though cycling emits less CO2 than transportation via car, the diet used to fuel that cycling has a very large impact on efficiency & emissions.

Ride details

Time
hour
minutes
Total CO2 emissions
602 g CO2
Emissions per kilometer
30.11 g CO2/km
Most similar mode of transportation
Tram – 29 g CO2/km

How is it calculated?

To estimate the amount of energy used, wattage of the rider is calculated using this formula, with the weight fixed at 85kg. Think of wattage as the horsepower of a car or other motor vehicle.

To calculate the calories burned for a given wattage, the following formula is used:Energy (kcal) = Power (w) * Time (h) * 3.6 This helps us estimate the amount of energy used for the given power. More reading about it.

To calculate the CO2 impact of a ride, CO2 footprint of different diets are sourced from O'Malley, Willits-Smith, Rose 2023:

Dietkg CO2 / 1000 kcal
Vegan0.69 kg CO2 / 1000 kcal
Vegetarian1.16 kg CO2 / 1000 kcal
Pescatarian1.66 kg CO2 / 1000 kcal
Omnivore2.23 kg CO2 / 1000 kcal
Paleo2.62 kg CO2 / 1000 kcal
Keto2.91 kg CO2 / 1000 kcal

The calculation assumes a non-electric bike. An electrically assisted bike will be much more efficient, though exact numbers depend on level of assistance.

Walkthrough

With the data provided before, the average speed is 20km / 1h = 20.0 km/h.

The average power required for that speed is 56W.

Riding for the given time at that wattage requires 56W * 3.6 * 1h = 204.74 kcal,
which given the diet's impact of 2.23 g CO2/kcal, gives us a total CO2 emission of 456g CO2

Over the distance of 20 km, the emission per km is 22g CO2/km