FuelTripCost.

Driving cost tool

Cost Per Mile Calculator

Turn fuel economy and pump price into a fuel-only rate for each mile or kilometre, then use the same assumptions to compare distances.

For pricing a detour, comparing routes, estimating repeat drives, or isolating the fuel portion of a mileage cost.

Estimate fuel cost

Enter your distance, vehicle economy, and fuel price. Choose a unit preset before entering values.

Units and currency
Enter the price you expect to pay. No live prices are used.

Results are estimates based on your entries. Actual fuel use and costs may vary with traffic, weather, vehicle condition, load, driving style, route changes, and fuel prices. No live prices or route distances are used.

How to use this calculator

  1. Select matching units.
  2. Enter a positive distance, economy, and price.
  3. Calculate and read cost per mile or kilometre separately from total cost.
  4. Recalculate when price or real-world economy changes.

Formula and variables

  • US cost per mile = price per gallon ÷ US MPG
  • Trip-based rate = fuel cost ÷ distance
  • Metric cost per km = L/100 km × price per litre ÷ 100

What each input means

  • Economy changes fuel used per unit of distance.
  • Price changes money spent without changing physical consumption.
  • Distance changes the total but not the rate when other inputs stay fixed.

Worked examples

25 MPG at $3.50

$3.50 ÷ 25 = $0.14 per mile; 100 miles costs $14.

30 MPG at $3.60

$3.60 ÷ 30 = $0.12 per mile; 250 miles costs $30.

Metric

At 6.5 L/100 km and €1.80 per litre, fuel is €0.117 per km; 500 km costs €58.50.

Real-world factors

  • The rate is stable only while price and economy remain similar.
  • City and motorway segments may have different rates if economy changes.

When to use it

  • Estimate a detour.
  • Compare recurring routes.
  • Separate fuel from ownership cost.

Common mistakes

  • Calling fuel cost the full cost of driving.
  • Mixing price per litre with an MPG formula.

Limits of the estimate

Excludes depreciation, finance, insurance, maintenance, tires, taxes, parking, tolls, and time. It is not a reimbursement rate.

Questions about this calculator

Is fuel cost per mile the full driving cost?

No. It covers fuel only; a full rate needs ownership and other trip costs.

Why does round trip not change the rate?

Cost and distance both double, so their ratio stays constant if economy and price do not change.

Related calculators and guides

Fuel Cost CalculatorRoad Trip Fuel CalculatorGas Mileage CalculatorCalculation methodology