Calculatrices du quotidien
Dix-sept outils simples pour les chiffres du quotidien — pourboire, pourcentages, prêts, TVA, épargne, dettes, marge, coût carburant, IMC et plus. Choisissez-en un pour commencer.
Pourboire
Pourcentage
Remise
TVA
Partage de l'addition
Convertisseur d'unités
Prêt & hypothèque
Hypothèque
Convertisseur de salaire
Intérêts composés
IMC & calories
Date & âge
Heures & durée
Remboursement de dette
Surface
Marge & marque
Coût du carburant
Fuel Cost Calculator — what a trip costs in fuel
This fuel cost calculator works out how much fuel a journey needs and what it costs, from the distance, your vehicle's fuel economy and the price of fuel. Switch between metric (kilometres, litres per 100 km, price per litre) and US units (miles, miles per gallon, price per gallon).
How the cost is calculated
In metric, fuel used is distance ÷ 100 × consumption, so a 300 km trip at 7 L/100 km burns 21 litres. In US units, fuel used is distance ÷ miles-per-gallon. The trip cost is simply the fuel used multiplied by the price, and the calculator also shows the cost per kilometre or mile.
Watch the gallon
A US gallon (3.785411784 litres, exact) is smaller than a UK imperial gallon (4.54609 litres, exact), so a UK mpg figure is not the same as a US one. This calculator's US mode uses the US gallon. If your economy is quoted in litres per 100 km, use metric mode to avoid mixing the two.
Convert fuel economy: mpg to L/100 km
Miles per gallon and litres per 100 km run in opposite directions — higher mpg is better, lower L/100 km is better. Because a US and a UK gallon differ, the conversion factor differs too:
| mpg (US) | L/100 km |
|---|---|
| 15 | 15.68 |
| 20 | 11.76 |
| 25 | 9.41 |
| 30 | 7.84 |
| 35 | 6.72 |
| 40 | 5.88 |
| 45 | 5.23 |
| 50 | 4.70 |
Formula: L/100 km = 235.21 ÷ mpg(US), or 282.48 ÷ mpg(UK). Derived from exact unit definitions (NIST): 1 US gal = 3.785411784 L, 1 UK gal = 4.54609 L, 1 mile = 1.609344 km.
Planning a journey
Use it to compare routes, split fuel costs for a shared trip, or estimate a monthly commute — multiply the one-way cost by the number of trips. Real consumption varies with speed, load, traffic and weather, so treat the result as a close estimate.
Cutting the cost per mile
The two levers are fuel economy and fuel price. Steady speeds, correct tyre pressure and less weight all improve economy; and a cheaper price per litre or gallon lowers every trip. Even a small change in consumption adds up over a year of driving.
Example
A 500 km trip at 6.5 L/100 km with fuel at 1.80 per litre needs about 32.5 litres and costs roughly 58.50 — about 0.12 per kilometre.
FAQ
How do I calculate the fuel cost of a trip?
Enter the distance, your fuel economy and the fuel price. In metric, fuel used is distance ÷ 100 × litres per 100 km; the cost is that fuel times the price.
What units should I use?
Use metric mode for kilometres, litres per 100 km and price per litre, or US mode for miles, miles per gallon and price per gallon. Keep all three inputs in the same system.
Is a US gallon the same as a UK gallon?
No — a US gallon is 3.79 litres and a UK gallon is 4.55 litres, so their mpg figures differ. This tool's US mode uses the US gallon; for UK figures, convert to litres per 100 km and use metric.
Why is my real fuel use different?
Actual consumption changes with speed, traffic, load, air conditioning and weather. The calculator uses your stated economy, so treat the result as a close estimate.
How do I estimate a monthly commute?
Work out the cost of one trip, then multiply by how many trips you make. Doubling a one-way cost gives a round trip.