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Fuel Cost Calculator

Work out the fuel cost of any trip from the distance, your car's fuel economy and the fuel price. Switch freely between miles or kilometres, MPG, km/L or L/100 km, price per gallon or litre, and your currency — then add a round trip or split the cost between passengers.

Round trip
people
Total fuel cost
$35.00
10.00 gallons of fuel for this trip.
Cost per person$35.00
Cost per mile$0.12
Per 100 miles$11.67
Trip summary
Fuel needed
10.00 gal
Total distance
300 mi
Round-trip cost
$70.00
Total cost
$35.00

How to use the fuel cost calculator

It updates as you type — no button to press:

1
Enter the distance — the one-way trip length, in miles or kilometres.
2
Set your fuel economy — your car's MPG, km/L or L/100 km. It is on your dashboard computer or the car's spec sheet.
3
Enter the fuel price — pick your currency and whether it is per gallon or per litre.
4
Add a round trip or split it — toggle round trip for there-and-back, and set how many people share the cost.

How fuel cost is calculated

The idea is simple — the only work is converting units so they line up:

fuel used = distance ÷ fuel economy
total cost = fuel used × fuel price

Worked example. A 300-mile trip, 30 MPG, fuel at $3.50 per gallon:

Fuel used — 300 ÷ 3010 gallons
Cost — 10 × $3.50$35.00
Round trip (600 miles)$70.00

MPG, km/L and L/100 km explained

Fuel economy is measured in a few different ways, and bigger is not always better — it depends on the unit:

MPG — miles per gallon
Common in the US and UK. Higher is better. Remember a UK gallon is ~20% bigger than a US gallon, so UK MPG figures look higher.
km/L — kilometres per litre
Used across much of Asia. Higher is better — more distance from each litre.
L/100 km — litres per 100 km
Standard in Europe and Australia. Here lower is better — it is fuel used, not distance travelled.

How to lower your fuel costs

Small habits add up over a year of driving:

  • Ease off. Smooth acceleration and steady speeds beat hard starts and stops — highway economy drops sharply above ~60 mph.
  • Check tyre pressure. Under-inflated tyres can cost several percent in economy.
  • Drop the weight and drag. Clear the boot and remove roof racks when you are not using them.
  • Combine trips. A warm engine is far more efficient than several cold starts.
  • Compare prices. A few cents per gallon adds up — use the calculator to see exactly how much.

Frequently asked questions

Enter the trip distance, your vehicle's fuel economy, and the price of fuel. The calculator works out how much fuel the trip uses and multiplies it by the price. In short: fuel used = distance ÷ fuel economy, and cost = fuel used × fuel price.