Calculate your vehicle's fuel economy in km/L, L/100 km and mpg from distance and fuel used.
Divide the distance driven by the fuel used. 400 km on 32 litres is 12.5 km/L — 8 L/100 km or 29.4 mpg (US). Fill the tank, reset the trip meter, drive, then refill and note the litres added.
The Gas Mileage Calculator turns a distance and an amount of fuel into fuel economy in every common unit: kilometres per litre (used in India), litres per 100 km (used in Europe), miles per US gallon and miles per UK (imperial) gallon. Add a fuel price to see the cost per kilometre and per mile and the total fuel cost.
Tracking mileage over several fills shows whether a vehicle is running efficiently or needs servicing. To plan a trip's fuel budget use the Fuel Cost Calculator.
The calculator converts everything to kilometres and litres, then to each unit.
| Distance / fuel | km/L | L/100 km | mpg (US) |
|---|---|---|---|
| 400 km on 32 L | 12.5 | 8 | 29.4 |
| 300 mi on 10 US gal | 12.75 | 7.84 | 30 |
| 500 km on 25 L | 20 | 5 | 47.04 |
| 250 km on 20 L | 12.5 | 8 | 29.4 |
| km/L | L/100 km | mpg (US) | mpg (UK) |
|---|---|---|---|
| 8 | 12.50 | 18.8 | 22.6 |
| 10 | 10.00 | 23.5 | 28.2 |
| 12 | 8.33 | 28.2 | 33.9 |
| 15 | 6.67 | 35.3 | 42.4 |
| 18 | 5.56 | 42.3 | 50.8 |
| 20 | 5.00 | 47.0 | 56.5 |
| 25 | 4.00 | 58.8 | 70.6 |
Use the full-tank method: fill the tank to the first click, note the odometer or reset the trip meter, drive normally, then refill to the same point and record the litres added. Do this over a few tanks and average the results — a single reading can be skewed by how the pump clicks off.
Divide the kilometres driven by the litres of fuel used since the last full tank. 400 km on 32 L is 12.5 km/L.
It depends on the vehicle. Many small petrol cars deliver 15–22 km/L and diesel hatchbacks and hybrids can exceed that; large SUVs often give 8–12 km/L.
Divide 100 by the km/L figure. 12.5 km/L is 8 L/100 km.
Multiply km/L by 2.352 for US mpg or by 2.825 for UK mpg. 12.5 km/L is about 29.4 mpg (US).
Because a UK gallon (4.546 L) is larger than a US gallon (3.785 L), the same car has a higher UK mpg figure.
Driving style, speed, traffic, tyre pressure, load, AC use, engine condition and the type of fuel.
Enter the fuel price: the calculator divides the price per litre by km/L to give the cost per kilometre.
Odometers can read a few percent high, so verify with a known distance for best accuracy.
The litres of fuel needed to drive 100 km. Lower is better — the opposite of km/L, where higher is better.
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