🚗 Cost Per Mile Calculator
By ToolNimba Finance Team · Reviewed by ToolNimba Editorial Review, personal finance content · Updated 2026-06-19
This calculator gives an estimate only. Your real cost per mile depends on live fuel prices, your actual fuel economy in mixed driving, and costs this tool does not include such as insurance, depreciation, tyres and finance. Treat the figure as a guide, not financial advice, and confirm rates with your own records before billing or budgeting.
This cost per mile calculator works out how much each mile of driving actually costs you. Enter your fuel price and your vehicle fuel economy and it returns the fuel cost per mile. Add an optional maintenance figure to get a fuller total cost per mile, and enter a trip distance to see what a journey costs. Switch between US units (price per gallon and MPG) and metric units (price per litre and L/100km) with one tap.
What is the Cost Per Mile Calculator?
Cost per mile is simply what it costs to move your vehicle one mile. The largest variable cost is usually fuel, and the fuel part is easy to work out: divide the price you pay for a unit of fuel by how far that unit takes you. In US units that is fuel price per gallon divided by miles per gallon (MPG). A car doing 30 MPG on $3.50 fuel costs 3.50 / 30 = about $0.117 per mile in fuel.
Metric figures need one extra step because economy is quoted as litres per 100 km (L/100km) rather than distance per unit. Cost per kilometre is price per litre times L/100km divided by 100. To compare like for like with US numbers this tool then converts kilometres to miles, using 1 km = 0.621371 miles. Lower L/100km means a more efficient car, the opposite direction to MPG where higher is better, which is a common source of confusion when comparing vehicles across regions.
Fuel is not the whole story. Running a vehicle also wears out tyres, brakes, oil and other parts, and serious cost-per-mile figures used by fleets and the self-employed add a maintenance allowance per mile on top of fuel. This calculator lets you add that figure so the total reflects more than the pump price. Bigger ownership costs like insurance, depreciation and finance are not per-mile in the same way, so they are left out here, but it is worth remembering they push the true cost of motoring well above the fuel-plus-maintenance number.
When to use it
- Working out the fuel cost of a specific trip before you set off, so you can budget or split it with passengers.
- Setting a fair mileage reimbursement or charging clients for travel as a self-employed worker.
- Comparing two cars by their real running cost per mile rather than just the sticker price or headline MPG.
- Deciding whether driving or another option (train, flight, rideshare) is cheaper for a given journey.
How to use the Cost Per Mile Calculator
- Choose your unit system: US (gallon, MPG) or metric (litre, L/100km).
- Enter the fuel price you pay per gallon or per litre.
- Enter your fuel economy: MPG in US mode, or L/100km in metric mode.
- Optionally add a maintenance cost per mile and a trip distance.
- Read off the fuel cost per mile, total cost per mile, and the trip cost.
Formula & method
Worked examples
A car doing 30 MPG, fuel at $3.50 per gallon, with no maintenance figure, on a 100 mile trip.
- Fuel cost per mile = 3.50 / 30 = 0.11667
- Total cost per mile = 0.11667 + 0 = 0.11667
- Trip cost = 0.11667 x 100 = 11.67
Result: Fuel cost about $0.117 per mile, trip cost about $11.67
A car using 8 L/100km, fuel at 1.60 per litre, plus 0.05 per mile maintenance, on a 160 km trip.
- Cost per km = 1.60 x 8 / 100 = 0.128
- Fuel cost per mile = 0.128 / 0.621371 = 0.20600
- Total cost per mile = 0.20600 + 0.05 = 0.25600
- Trip distance in miles = 160 x 0.621371 = 99.42
- Trip cost = 0.25600 x 99.42 = 25.45
Result: Fuel cost about $0.206 per mile, total about $0.256 per mile, trip cost about $25.45
Fuel cost per mile by MPG at different US fuel prices (price per gallon / MPG)
| Fuel economy | $3.00/gal | $4.00/gal | $5.00/gal |
|---|---|---|---|
| 20 MPG | $0.150 | $0.200 | $0.250 |
| 30 MPG | $0.100 | $0.133 | $0.167 |
| 40 MPG | $0.075 | $0.100 | $0.125 |
| 50 MPG | $0.060 | $0.080 | $0.100 |
Quick conversions between US and metric driving figures
| Quantity | Relationship |
|---|---|
| 1 mile | 1.60934 km |
| 1 km | 0.621371 miles |
| 1 US gallon | 3.78541 litres |
| MPG to L/100km | 235.215 / MPG |
Common mistakes to avoid
- Mixing up MPG and L/100km direction. Higher MPG means a more efficient car, but with L/100km lower is better. Entering an L/100km value into an MPG field (or the reverse) gives a wildly wrong cost, so pick the right unit mode first.
- Treating fuel cost as the whole cost per mile. Fuel is only part of the picture. Tyres, servicing, insurance, depreciation and finance all add up. The fuel-only figure understates the true cost of running a vehicle, which is why a maintenance field is included.
- Using the official MPG instead of your real MPG. Manufacturer or label MPG is measured in ideal conditions. Real-world economy in city traffic, cold weather or with a loaded car is often lower, so the actual cost per mile is usually higher than the brochure suggests.
- Forgetting prices and economy change. Fuel prices move week to week and economy varies with how and where you drive. A cost per mile is a snapshot, so recheck it with current numbers before relying on it for budgeting or billing.
Glossary
- Cost per mile
- The total cost to drive one mile, here fuel cost per mile plus any maintenance cost per mile.
- MPG
- Miles per gallon, a measure of fuel economy used in the US and UK where a higher number is more efficient.
- L/100km
- Litres of fuel used per 100 kilometres, the metric economy measure where a lower number is more efficient.
- Maintenance per mile
- An allowance added per mile for wear items like tyres, brakes, oil and servicing, separate from fuel.
- Fuel economy
- How far a vehicle travels on a given amount of fuel, expressed as MPG or L/100km.
Frequently asked questions
How do I calculate cost per mile?
For fuel, divide the price you pay per gallon by your miles per gallon. So $3.50 fuel at 30 MPG is 3.50 / 30, about $0.117 per mile. Add a maintenance cost per mile if you want a fuller total. This calculator does all of it for you.
How do I work out cost per mile from L/100km?
First find cost per km: price per litre times L/100km divided by 100. Then divide by 0.621371 to convert to cost per mile. For example 1.60 per litre at 8 L/100km gives 0.128 per km, which is about $0.206 per mile.
What is a typical fuel cost per mile?
It depends on the car and fuel price, but many everyday petrol cars land between roughly $0.10 and $0.20 per mile in fuel alone. Efficient hybrids can be lower and large trucks much higher. Use your own price and MPG for an accurate figure.
Should I include maintenance in cost per mile?
If you want a realistic running cost, yes. Fleets and self-employed drivers add a per-mile allowance for tyres, servicing and other wear. Enter it in the maintenance field and the total cost per mile will include it on top of fuel.
Does this include insurance and depreciation?
No. Insurance, depreciation and finance are large costs but they are not really per-mile, so they are left out. The true cost of owning a car is higher than the fuel-plus-maintenance figure shown here.
Can I use this for electric vehicles?
Not directly, because the inputs assume liquid fuel measured in gallons or litres. For an EV you would calculate cost per mile from electricity price per kWh and the car efficiency in miles per kWh instead.
Sources
- Gas Mileage Tips and Fuel Economy , U.S. Department of Energy, fueleconomy.gov
- Standard Mileage Rates , U.S. Internal Revenue Service