Bike vs Car Cost Calculator

How to use the calculator

1. Your commute. Enter the one-way distance. With “2 trips per day” we count there and back. Under “Weeks per year,” take out vacation and the days you know you wouldn’t ride: 44 weeks leaves room for vacation, holidays and the odd day of bad weather.
2. The car you leave at home. Pick one of two ways to count it:
   • Fuel economy and gas price: your real mpg (the one on the trip computer), the price per gallon and what maintenance costs you per mile.
   • Cost per mile: a single all-in figure. If you don’t have one, the IRS business rate of 76 cents a mile is a common reference for the full cost of driving your own car.
3. Parking and fixed costs. If you pay for a garage, meters or a lot when you drive, add it. If the bike lets you sell the car (or skip buying a second one), enter the insurance, registration and inspection under “Fixed costs.”
4. Your alternative. A regular bike or an e-bike, with the purchase price and what you will spend keeping it running each year. For an e-bike we add the cost of charging it.

The calculator works in US units (miles, mpg, dollars per gallon) or metric. Switch with the US / Metric buttons; the result is the same either way.

How we calculate it

Miles per year = miles per trip × trips per day × days per week × weeks per year

Yearly car cost

Fuel = miles ÷ mpg × price per gallon

Maintenance = miles × maintenance cost per mile

Car total = fuel + maintenance + parking × 12 + fixed costs

In cost-per-mile mode, the total is miles × cost per mile + parking + fixed costs.

Yearly bike cost

Bike total = yearly maintenance + miles × Wh per mile ÷ 1,000 × price per kWh (e-bike only)

Results

Yearly savings = car total − bike total

Months to pay off the bike = purchase price ÷ (yearly savings ÷ 12)

CO₂ avoided = gallons not burned × CO₂ per gallon − e-bike kWh × CO₂ per kWh of the grid

We don’t subtract the bike’s price from the yearly savings: we treat it as an investment that those savings pay back. Below the result you will also see the five-year balance, after paying for the bike.

Default values and where they come from

Gas prices change every week and vary a lot from state to state. For a sharper result, enter the price at your usual station and the rate on your electric bill.

Savings chart

Round trip, 5 days a week and 44 weeks a year, compared with a 22.2 mpg gas car counting fuel and maintenance (31¢ a mile). Regular bike at $700 with $100 a year of maintenance; e-bike at $2,000 with $180 a year.

Electricity is the smallest line in an e-bike budget: filling a 500 Wh battery costs about 9 cents before charger losses (0.5 kWh × 18.2¢) and about 11 cents with them, because roughly 0.6 kWh comes out of the wall. That’s why the calculator uses the energy measured at the outlet, 11.3 Wh per mile: 100 miles cost about 20 cents, or $4.51 a year on the default commute. For electricity costs per mile and per year at other prices per kWh, see the e-bike cost per mile chart.

Where an e-bike really pays off fast is on longer commutes, or when parking or fixed costs are part of the picture. On a 5-mile commute with a $100-a-month parking spot, the e-bike saves about $1,702 a year and pays for itself in 14 months. If you also sell the car and drop $2,098 a year of insurance (AAA’s 2026 average for a new car), the e-bike saves about $2,600 a year and pays for itself in about 9 months, even without parking.

Driving at the IRS rate

If you switch to “Cost per mile” and use the IRS business rate of 76 cents, the same 5-mile commute costs about $1,672 a year by car, and a $700 bike pays for itself in about 5 months. That figure is high on purpose: it spreads insurance, depreciation and registration over every mile. Use it only if biking would really let you drive a lot less or give up a car. If the car stays in the driveway, the fuel-and-maintenance mode is the honest one.

What the calculator leaves out (and counts in favor of the bike)

• Time. On short city trips, door to door, a bike is often about as fast as a car, because you don’t circle for parking or sit at the on-ramp.
• Health. Half an hour of riding five days a week adds up to the 150 minutes a week of moderate activity that the CDC recommends as a minimum. You can estimate the energy you burn with the cycling calorie calculator.
• Cold starts. On short trips the engine never warms up and burns a good deal more than its average mpg suggests.

And what counts against it: clothing, a lock and lights (include them in the purchase price), and the days you’ll end up driving or taking transit anyway (take them out under weeks per year).

Common mistakes

• Counting only gas. Tires, oil changes, brakes and repairs cost money too: AAA puts them at 11.7 cents a mile on average, about $1,755 a year if you drive 15,000 miles.
• Using the window-sticker mpg. It’s a lab figure. Real-world fuel economy, especially in town, is usually worse.
• Forgetting parking. In many downtowns it is the biggest saving of all.
• Comparing with a car you’ll keep anyway. If the car stays, its fixed costs don’t go away: leave them out.

Before you buy

If you don’t have a bike yet, the Which bike should I buy? quiz tells you what type fits your commute and budget. If you’re thinking about an e-bike, check how many miles the battery will give you. E-bike classes and the rules of the road for riding are in the bike laws section.

Updated October 19, 2026 ·Report an error on this page