Calculate Fuel Cost for a Trip
Enter the distance, your car's fuel economy and the fuel price to estimate the fuel cost of a trip. It works in miles or kilometres, US or UK MPG, L/100 km or km/L, and with prices per gallon or per litre, with today's average gas and petrol prices for the US, the UK and every EU country.
Your trip
Your car & fuel price
Sharing & extras optional
Same trip with a different car
How to calculate the fuel cost of a trip
Three numbers decide what a drive costs in fuel: how far you go, how much fuel your car uses and what you pay for it. The calculator above takes them in whatever units you use (miles or kilometres, MPG or litres per 100 km, a price per gallon or per litre) and works out the rest. The maths is simple enough to do by hand:
With L/100 km: fuel cost = distance in km × L/100 km ÷ 100 × price per litre
Cost per person is the total divided by the number of people sharing, and a return trip simply doubles the distance. Add tolls and parking separately; they don't depend on fuel.
Worked examples with today's average prices
- United States: a 300-mile drive in a car that gets 28 MPG uses 10.7 gallons. At the national average of $4.23/gal, that is about $45.28 in gas.
- United Kingdom: 200 miles at 45 MPG (UK gallons) needs 20.2 litres of petrol. At 174.1p/L the petrol cost for the trip is about £35.18.
- Europe: 500 km in a car using 6.5 L/100 km takes 32.5 litres. With petrol at €2.214/L in Germany, the fuel costs about €71.96.
What you need to estimate gas cost for travel
1. The distance
Use the driving distance from Google Maps, Apple Maps or your sat nav rather than a straight-line distance; roads are usually 20–30% longer. Enter it one way and tick Return trip if you are driving back. For a road trip with several stops, add the legs together.
2. Your car's fuel economy
The most accurate number is your own: most cars show average MPG or L/100 km on the dashboard. Otherwise use the official figure (the EPA combined MPG in the US, the WLTP figure in the UK and Europe), and expect real motorway driving with luggage to use a little more. The fuel consumption calculator works out your real MPG from a full tank.
3. The fuel price
When you choose a country, the calculator fills in the latest national average for petrol or diesel. Prices vary by region, brand and road (motorway services are usually dearest), so type in what you actually see at the pump. All averages are listed on our fuel prices by country page.
Miles or kilometres, US or UK gallons
A fuel cost calculator is only as good as its units, and fuel economy is measured three different ways:
- MPG (US) – miles per US gallon of 3.785 litres. Higher is better.
- MPG (UK) – miles per imperial gallon of 4.546 litres. Because the gallon is 20% bigger, the same car shows a 20% higher MPG in the UK: 30 US MPG is 36 UK MPG.
- L/100 km – litres used per 100 kilometres, used across Europe. Lower is better. Some countries also use km/L.
| MPG (US) | MPG (UK) | L/100 km | km/L |
|---|---|---|---|
| 15 | 18.0 | 15.7 | 6.4 |
| 20 | 24.0 | 11.8 | 8.5 |
| 25 | 30.0 | 9.4 | 10.6 |
| 30 | 36.0 | 7.8 | 12.8 |
| 35 | 42.0 | 6.7 | 14.9 |
| 40 | 48.0 | 5.9 | 17.0 |
| 50 | 60.0 | 4.7 | 21.3 |
Need more conversions? Use the MPG to L/100 km converter.
How to cut the fuel cost of a road trip
- Slow down a little. Air resistance rises steeply with speed, so most cars use noticeably more fuel at 75 mph (120 km/h) than at 65 mph (105 km/h).
- Check your tyre pressures before you set off, especially with a full load.
- Pack light and remove roof boxes and bike racks you don't need; they add drag.
- Fill up before the motorway. Service-station prices are often well above the national average.
- Share the ride. Four people in one car pay a quarter each. The gas money calculator splits it fairly, even when people join for part of the way.