Car vs Bike Commute Calculator — Cost, CO₂ & Time
Enter your commute distance, days per week, car running costs and bike maintenance to compare annual spending, CO₂ and commute hours between driving and cycling.
km
km/L
per L
km/h
km/h
Total annual car cost minus total annual bike cost
- 1
Annual trips
5 × 52 = 260 - 2
Annual round-trip distance
2 × 10 × 260 = 5,200 km - 3
Annual fuel consumed
5,200 ÷ 12 = 433.3 L - 4
Annual fuel cost
433.3 × 1.8 = 780 - 5
Annual car total
780 + 3,000 = 3,780 - 6
Annual saving by cycling
3,780 − 200 = 3,580
How does this calculator work?
Annual car fuel = (2 × d × days × 52 / km/L) × fuel price. Add insurance, registration and depreciation for total car cost. CO₂ saved = litres × 2.31 kg/L. Subtract annual bike maintenance to find the saving. For most urban commutes under 20 km, cycling saves hundreds to thousands per year and cuts significant CO₂.
Formula
How this is calculated
The calculator totals annual costs for each mode across all commuting trips. For the car, it computes the round-trip distance per year (one-way distance × 2 × days/week × 52 weeks), divides by fuel efficiency (km/L) to find litres consumed, then multiplies by the fuel price. Annual fixed costs — insurance, registration, depreciation, servicing — are added on top. The default fixed-cost figure is an illustrative 2024 estimate; replace it with your actual numbers for an accurate comparison.
For the bike, only annual maintenance is counted — no depreciation or insurance is assumed. CO₂ savings use the established emission factor for petrol combustion: 2.31 kg of CO₂ per litre burned (derived from the known carbon content of petrol and the stoichiometry of combustion). Diesel is slightly higher at 2.68 kg/L; if you drive diesel, scale the result accordingly or reduce the reported efficiency.
Commute time is found by dividing the annual round-trip kilometres by the average speed of each mode. Average car speed should reflect real urban conditions including traffic lights and parking time, not the road speed limit. Cycling sometimes takes similar time to driving for distances under 10 km. The calculator does not value the health benefits of cycling (exercise replacing gym time) or factor in e-bike electricity costs, which are small but non-zero.
Frequently asked questions
Insurance premiums, vehicle registration, road tax, annual servicing and depreciation (the car's loss of resale value per year). Depreciation is typically the largest item — a car losing €2,000 per year in value is a real cost even if it is invisible day-to-day. The default is a rough 2024 European estimate; adjust it to your real figures.
Burning one litre of petrol (~0.74 kg) releases the carbon it contains as CO₂. Petrol is about 86% carbon by mass; combustion converts each carbon atom to CO₂ (44/12 ≈ 3.67× the carbon weight). The net factor works out to approximately 2.31 kg CO₂ per litre — a fixed physical chemistry result, not an estimate.
Human-powered cycling produces negligible direct CO₂ per kilometre — the extra calories burned are a tiny fraction of a car's emissions. Electric bikes add a small indirect amount from grid electricity, which varies by country but is still far lower than a petrol car. This calculator treats cycling as zero direct emissions.
Also known as
TG we-Calculate Editorial Team. (2026). Car vs Bike Commute Calculator — Cost, CO₂ & Time [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/car-vs-bike-calculator
TG we-Calculate Editorial Team. "Car vs Bike Commute Calculator — Cost, CO₂ & Time." TG we-Calculate. 2026. https://we-calculate.com/calculator/car-vs-bike-calculator.
TG we-Calculate Editorial Team, "Car vs Bike Commute Calculator — Cost, CO₂ & Time," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/car-vs-bike-calculator
@misc{wecalculate_car_vs_bike_calculator, title = {Car vs Bike Commute Calculator — Cost, CO₂ & Time}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/car-vs-bike-calculator}}, year = {2026}, note = {TG we-Calculate} }
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