Fuel Cost Calculator
The fuel cost of a trip from distance, consumption (L/100km) and fuel price.
- Fuel used (litres)21.0
- Trip fuel cost$37.80
Inputs used
- Distance300 km
- Fuel consumption7 L/100km
- Fuel price per litre$1.80
About this calculator
Trip fuel cost is distance × consumption × price: a 300 km trip in a car using 7 L/100km burns 21 litres, which at 1.80 per litre costs 37.80.
Consumption in litres per 100 km is the figure on most car spec sheets outside the US. If you know miles per gallon instead, 235.2 divided by mpg (US) gives L/100km. Real-world consumption is typically 10–20% above the official figure, so nudge it up for motorway speeds, a loaded car or city traffic.
For a return trip, double the distance — and to split costs between passengers, divide the result by the number of people.
Frequently asked questions
How do I convert miles per gallon to L/100km?
Divide 235.2 by the US mpg figure (or 282.5 by UK/imperial mpg): a car rated 33 mpg US uses about 7.1 L/100km. The conversion is inverse — higher mpg means lower litres per 100 km.
Why does my car use more fuel than the official figure?
Official figures come from standardized laboratory cycles. Real-world driving — motorway speeds, short cold-start trips, city traffic, a loaded car, air conditioning — typically runs 10–20% above them, so nudge the consumption figure up for realistic costs.
What does driving cost per kilometre?
In fuel alone: consumption × price ÷ 100. At 7 L/100km and 1.80 per litre that's about 12.6 cents per km, or roughly $38 per 300 km trip. Ownership costs (depreciation, insurance, servicing) typically double or triple the true per-km figure.
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Results are informational only — not financial, medical or legal advice.