Fuel Cost Calculator
Fuel cost is two multiplications and one division: distance into litres, litres into money, and money into a rate you can reuse. The only real traps are the units and a consumption figure that runs backwards.
Cost of the fuel for the trip
55.6875
- Litres needed
- 33.75
- Cost per kilometre
- 0.1238
- Cost per 100 kilometres
- 12.375
Values update as you type. This calculator covers the single scenario its formula assumes — see Common Mistakes for what it leaves out.
The formula this calculator uses
Fuel cost = (distance x consumption / 100) x price per litre
- distance
- Trip distance in kilometres, matching the consumption unit
- L/100km
- Consumption — litres burned per 100 kilometres; lower is better
- price
- Fuel price per litre, in one currency throughout
- cost
- Total fuel cost for the trip, before tolls and parking
How to check the result by hand
- 1
Turn distance and consumption into litres
Multiply the trip distance by the consumption in litres per 100 kilometres, then divide by 100. For 450 kilometres at 7.5 litres per 100 kilometres that is 450 x 7.5 ÷ 100 = 33.75 litres. The division by 100 is what converts a per-hundred-kilometre rate into the litres an individual trip actually burns.
- 2
Multiply litres by the price per litre
33.75 litres at 1.65 per litre is 33.75 x 1.65 = 55.6875. Keep the price in the same currency and the same volume unit as the litres you just computed, otherwise the total is meaningless even though the arithmetic is correct.
- 3
Divide by distance for the cost per kilometre
55.6875 ÷ 450 = 0.12375 per kilometre, and multiplying by 100 gives 12.375 per 100 kilometres. The per-kilometre figure is the one to reuse: it stays constant as long as consumption and price do, whatever the distance happens to be.
- 4
Swap in a realistic consumption figure
Replace the rated 7.5 with something closer to real driving, say 9.0 litres per 100 kilometres, and the same trip costs 66.825 instead of 55.6875. Running both figures side by side shows how much of a budget rests on an optimistic assumption.
- 5
Add the costs the fuel formula misses
Tolls, parking, congestion charges and the wear on tyres and brakes are all part of what a journey costs. A 55.6875 fuel bill with 12 of tolls and parking is really 67.6875, and leaving those out understates the trip by nearly a fifth.
For worked examples, common mistakes and the limits of this formula, read the full How To Calculate Fuel Cost page.