ToolCalcu

Fuel Cost Calculator

Estimate how much fuel a trip needs and what it costs. Use the units you know: km or miles, L/100 km, km/L or mpg, price per liter or gallon.

Your trip

Enter the figure in the unit chosen next to it. Lower is better for L/100 km; higher is better for km/L and mpg.

A US gallon is 3.785 L and a UK (imperial) gallon is 4.546 L, so the same mpg means different consumption in each system.

US gallon = 3.785 liters; UK (imperial) gallon = 4.546 liters. Choose the one your price refers to.

Result

Please correct the highlighted fields.
Estimated fuel cost
$37.80
Total distance
300 km
Fuel needed
21 L
Fuel needed (US gallons)
5.55 gal
Cost per 100 km
$12.60
Cost per mile
$0.20
Consumption (converted)
7 L/100 km

How the fuel cost is calculated

Fuel economy is first converted to liters per 100 km, so L/100 km, km/L and miles per gallon can all be used. The fuel needed is the distance times that consumption divided by 100, and the cost is the fuel times the price per liter.

A US gallon is 3.785411784 liters and an imperial (UK) gallon is 4.54609 liters, so mpg figures differ between the two. A mile is 1.609344 km. A round trip simply doubles the distance.

Formulas used

Liters = Distance (km) × (L/100 km) ÷ 100
Cost = Liters × Price per liter
L/100 km = 100 ÷ (km/L)  =  235.215 ÷ mpg (US)  =  282.481 ÷ mpg (UK)

Worked example

300 km at 7 L/100 km with fuel at 1.80 per liter:

  1. Fuel: 300 × 7 ÷ 100 = 21 liters
  2. Cost: 21 × 1.80 = 37.80

Estimated fuel cost: $37.80.

Assumptions and limits

  • Consumption and price are constant for the whole trip.
  • The cost is rounded to the cent.
  • The currency choice only changes how amounts are displayed. No exchange rates are applied.
  • Limits: distance up to 10,000,000, fuel economy up to 1,000 in the chosen unit and price up to 100,000.

Sources and references

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