Fuel Cost Calculator
Estimate the fuel cost of a trip from its distance, your fuel economy, and the price at the pump.
500 km at 7 L/100km and 1.80/L.
Cost climbs in a straight line with distance because the price and fuel economy are held fixed.
Economy convention: L/100km.
Fuel cost is the fuel a trip burns times its price. For a 500 km drive at 7 L/100km with fuel at 1.80 per litre, the trip uses 500 ÷ 100 × 7 = 35 litres, so the cost is 35 × 1.80 = 63.00. Doubling the distance or the price doubles the cost.
How trip fuel cost works
Every trip cost comes down to two numbers: how much fuel you burn and what that fuel costs. Work out the fuel first, then multiply by the price. The only wrinkle is which units your fuel economy uses. Most of the world quotes economy as litres per 100 km (a lower number is better), while the United States uses miles per gallon (a higher number is better). The calculator handles both — pick the convention that matches your car and fuel price, and it keeps distance, fuel, and price in matching units.
L/100km convention. In MPG mode: cost = distance ÷ MPG × price per gallon.
- 1 Measure the trip distance. Use kilometres with L/100km, or miles with MPG — here, 500 km.
- 2 Find the fuel used. In L/100km mode divide distance by 100 and multiply by the economy: 500 ÷ 100 × 7 = 35 litres.
- 3 Multiply fuel by the price. Multiply the litres (or gallons) by the price per unit: 35 × 1.80 = 63.00.
- 4 Read the cost per km. Divide the cost by the distance to compare trips: 63.00 ÷ 500 = 0.126 per km.
Trip cost at 7 L/100km and 1.80 per litre
Cost scales in a straight line with distance when economy and price stay fixed.
| Distance (km) | Fuel used (L) | Trip cost |
|---|---|---|
| 100 | 7 | 12.60 |
| 250 | 17.5 | 31.50 |
| 500 | 35 | 63.00 |
| 750 | 52.5 | 94.50 |
| 1,000 | 70 | 126.00 |
Reading the result
The numbers here are currency-agnostic — enter the price in whatever currency you pay, and the cost comes back in the same one. For a there-and-back journey, double the distance (or the final cost). Treat the answer as a planning estimate rather than an exact figure: real-world economy drifts with speed, traffic, terrain, load, air conditioning, and tyre pressure, so the fuel your car actually burns can sit a little above or below the rated figure you enter.