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GivenTool

Fuel cost calculator

Trip fuel cost from distance, your car’s consumption (L/100 km, km/L or MPG) and the fuel price, with round trips and a split between passengers.

Inputs

In any currency.

Calculated in your browser. Nothing you enter is sent anywhere. Updates as you type.

Trip fuel cost

Fuel used = distance × consumption, and cost = fuel used × price. With consumption in litres per 100 km: litres = km × L/100 km ÷ 100. A 300 km drive in a car that uses 7 L/100 km burns 21 litres; at 1.50 a litre that is 31.50, or 63.00 for the round trip, 21.00 each if three people share it.

Enter the consumption the way your car or country quotes it. L/100 km is used across Europe, the Gulf and Australia; km/L in much of Asia and Latin America; miles per gallon in the US and UK, where the gallons differ: a US gallon is 3.785 litres and an imperial (UK) gallon 4.546 litres. The conversions are L/100 km = 100 ÷ km/L = 235.215 ÷ MPG (US) = 282.481 ÷ MPG (UK). The result shows your figure in all four units, plus the cost per km or mile.

The price can be per litre or per US or UK gallon and in any currency, so the calculator works for petrol, diesel or LPG anywhere. Rated consumption figures are measured in test cycles and usually beat real driving: motorway speed, traffic, air-conditioning and a full car all raise consumption, so use your trip computer’s average if you have one.

How to use it

  1. Enter the one-way distance and choose kilometres or miles.
  2. Enter your car’s fuel consumption and pick its unit (L/100 km, km/L, MPG US or MPG UK).
  3. Enter the fuel price and whether it is per litre or per gallon.
  4. Tick round trip if you are coming back, set the number of people sharing, and read the total and per-person cost.

Frequently asked questions

How do I calculate fuel cost for a trip?

Litres needed = distance in km × L/100 km ÷ 100; cost = litres × price per litre. For 450 km at 8 L/100 km and 2.60 a litre: 450 × 8 ÷ 100 = 36 L, and 36 × 2.60 = 93.60.

How do I convert MPG to L/100 km?

Divide 235.215 by US MPG, or 282.481 by UK MPG. 30 MPG (US) is 7.84 L/100 km; 30 MPG (UK) is 9.42 L/100 km, because the imperial gallon is about 20% bigger.

Why is my real fuel cost higher than the calculator says?

Official consumption figures come from standardised laboratory tests. Real consumption is often 10 to 25% higher, more at high speed, in heavy traffic, with air-conditioning on full or with roof boxes and heavy loads. Enter your own measured average for a closer estimate.

How do I measure my car’s real consumption?

Fill the tank and reset the trip meter. At the next fill-up, note the litres added and the distance driven: L/100 km = litres ÷ km × 100. 42 litres after 560 km is 7.5 L/100 km.

Does it work for electric cars?

Not directly, because it works in litres or gallons. For an EV, multiply distance by consumption in kWh per 100 km, divide by 100 and multiply by your electricity price per kWh.

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