Car vs Bike Calculator
Compare the annual cost and carbon footprint of driving a car versus biking the same distance. See how much money and CO₂ you'd save by switching to a bike for your commute or local trips.
Formula
Car cost = (distance × 0.621 ÷ mpg) × fuel price
Savings = car cost − bike maintenance
CO₂ = gallons × 8.887 kg/gal
- Annual distance = weekly distance × 52 weeks.
- Fuel consumption = distance in miles ÷ fuel economy (mpg).
- Car cost includes only fuel here; full car cost (insurance, depreciation, etc.) would be much higher.
- Bike cost is maintenance only (tires, tune-ups). Initial bike purchase is not included.
- CO₂ emission factor: gasoline combustion releases ~8.887 kg of CO₂ per gallon (US EPA).
50 km/week, 30 mpg car, $3.50/gal fuel
Inputs
- Weekly Distance: 50 km
- Car Fuel Economy: 30 mpg
- Fuel Price: 3.5 $/gal
- Annual Bike Maintenance: 100 $
50 km/week = 2,600 km/year = 1,615 miles. At 30 mpg that's 53.8 gallons/year, costing ~$188. Bike maintenance = $100. Savings = $88/year, avoiding 478 kg CO₂.
Frequently asked questions
What costs are included?
Car cost here is fuel only; the full cost of car ownership (insurance, depreciation, repairs) is much higher. Bike cost is annual maintenance; a new bike purchase is excluded.
How much CO₂ does biking produce?
Biking produces zero direct emissions. The calculator shows how much CO₂ you avoid by not driving.
Is this realistic for long commutes?
For distances over ~20 km one-way, biking may not be practical daily. Consider it for shorter trips or combine biking with public transit.
What about e-bikes?
E-bikes use a tiny amount of electricity (~0.01–0.02 kWh/km), costing pennies per charge. They're still vastly cheaper and cleaner than cars.