E-Bike vs Car Savings Calculator

Enter the weekly miles you would actually ride instead of drive. Then enter your car's mpg, the local fuel price, and a per-mile allowance for maintenance, tyres and insurance wear. Finish with your electricity rate and the e-bike's watt-hours per mile.

Worked example: 50 miles a week, a 30 mpg car, $3.50 a gallon, a $0.10 allowance, $0.1883/kWh and 25 Wh a mile.

Fuel costs $3.50 ÷ 30 = $0.1167 a mile, so the car costs $0.2167 a mile in total. The e-bike costs 25 ÷ 1,000 × $0.1883 = $0.0047 a mile.

Over 50 × 52 = 2,600 miles, the car costs $563.33 and the e-bike $12.24. The difference is $551.09 a year. The e-bike's charging uses 65 kWh a year.

CO2 avoided is 8,887 g ÷ 30 mpg = 296 g a mile. Over 2,600 miles that is 0.77 metric tons a year.

Car cost per mile = Fuel price ÷ MPG + Operating allowance per mile.

E-bike cost per mile = (Wh per mile ÷ 1,000) × Electricity rate. This is kWh per mile times the price per kWh. At 25 Wh a mile, that is 0.025 kWh a mile.

Annual miles = Weekly miles × 52. Annual car cost = Annual miles × Car cost per mile. Annual e-bike cost = Annual miles × E-bike cost per mile.

Annual savings = Annual car cost − Annual e-bike cost. Monthly savings = Annual savings ÷ 12.

CO2 avoided (metric tons a year) = (8,887 g ÷ MPG) × Annual miles ÷ 1,000,000. The 8,887 g is EPA's figure for CO2 from burning one gallon of gasoline. The emissions from generating the charging electricity are not subtracted.

A longer commute changes more than the mileage. Take a rider going 10 miles each way, five days a week, which is 100 miles a week. They are replacing a 25 mpg car.

At higher speeds and with more hills, the e-bike uses 30 Wh a mile. Fuel stays at $3.50, the allowance at $0.10, and electricity at $0.1883.

The car now costs $0.24 a mile and the e-bike $0.0056 a mile. Over 5,200 miles, the car costs $1,248 and the e-bike $29.37, using 156 kWh of charging.

Savings are $1,218.63 a year, or $101.55 a month, and the switch avoids 1.85 metric tons of CO2.

The miles doubled, but savings grew by 2.2 times, because the thirstier car raised the cost of every mile replaced. The 20% higher energy use per mile barely matters: it adds under a cent a mile.

At the other end of the range, a 2-mile commute each way, which is 20 miles a week, replacing a 40 mpg hybrid saves just $190.10 a year and 0.23 metric tons of CO2. Short trips in an efficient car are where the case for an e-bike rests on convenience and health rather than money.

Battery replacement is not modelled. Battery wear can easily cost more per mile than the electricity itself. You can estimate it as: battery cost per mile = pack price ÷ (usable charge cycles × miles per charge).

Take a hypothetical $600 pack that lasts 500 cycles at 30 miles a charge. That works out to $0.04 a mile, more than eight times the charging cost in the first example. Use your own pack's price and rated cycle life, because both vary widely between models.

How to include it: savings equal miles × (car cost − e-bike cost), so any e-bike cost per mile can be subtracted from the car allowance instead. In the first example, entering $0.06 rather than $0.10 cuts savings from $551.09 to $447.09 a year. Tyres, brake pads and servicing can be added the same way.

Pick the allowance carefully. Set it to $0 and the first example saves only $291.09, fuel alone. The allowance should only include costs that really fall when you drive less, such as maintenance, tyres and pay-per-mile insurance. Fixed insurance, registration and time-based depreciation stay the same unless you get rid of the car.

This is a comparison of running costs, not a purchase decision. It leaves out the price of the e-bike, locks, lights and weather gear, and it does not work out a payback period.

Watt-hours per mile depend on assist level, rider and cargo weight, hills, speed and cold weather. The Wh figure a bike's display reports may be what the battery delivers, not what the charger draws from the wall. Charger losses make the wall figure somewhat higher.

The CO2 figure treats the e-bike as zero-emission. It does not subtract emissions from generating the electricity, from making the bike and battery, or from any unmodelled trips.

The results assume every mile you enter really replaces a car mile. Weather, cargo, route safety and trip chaining all reduce the miles a rider actually swaps, so enter a realistic weekly figure rather than your full commute.

If the choice is between an e-bike and a regular bike, the bike commute carbon and calorie calculator prices the same trip without a motor and adds the calories burned. On bad-weather days, the public transit vs driving calculator compares bus or rail fares with the full cost of driving.

The eco-commute and work-from-home calculator covers not travelling at all. If you are keeping a car but might change what powers it, the EV vs gas calculator compares cost per mile for an electric and a gasoline car. The fuel cost calculator prices a single trip's fuel on its own.