Fuel Economy Calculator
Calculate fuel economy from distance and fuel consumed
Fuel Economy Reference
| Category | km/L | Rating |
|---|---|---|
| Excellent | 20+ km/L | ★★★ |
| Good | 15–20 km/L | ★★☆ |
| Average | 10–15 km/L | ★☆☆ |
| Poor | Under 10 km/L | ☆☆☆ |
* Results are estimates based on input values. Actual fuel economy varies depending on driving conditions, road conditions, and vehicle condition.
How to calculate fuel economy
Fuel economy is distance divided by fuel used. With the tank-to-tank method you reset the trip meter when you fill up, then divide the distance driven by the amount of fuel it takes to fill up again. Drive 420 km on 28 L and you get 15.0 km/L. Enter the distance and the litres here and the result appears in km/L, L/100km and MPG at the same time.
Which unit is normal depends on where you are. Japan uses km/L (distance per litre), Europe uses L/100km (fuel needed per 100 km), and the United States uses MPG (miles per gallon). Note that km/L and L/100km run in opposite directions — higher is better for one, lower is better for the other — which is worth remembering when reading a foreign brochure.
Add a fuel price and the tool also works out what that trip cost and what 100 km costs. That makes it easy to estimate the monthly cost of a commute, or to see how much actually changes when you switch cars. Everything is calculated in the browser and none of the values you enter are sent anywhere.
Frequently asked questions
- What is the tank-to-tank method?
- Reset the trip meter at a fill-up, then divide the distance driven by the litres needed at the next fill-up. It reflects real driving conditions better than any published figure.
- What is the difference between km/L and L/100km?
- km/L is distance per litre, so higher is better. L/100km is fuel needed per 100 km, so lower is better. They are inverses of each other.
- Why is my real economy worse than the official figure?
- Official figures come from a standardised test cycle. Idling at lights, air conditioning, traffic jams and lots of short trips all push real-world consumption up.
- Is MPG based on US gallons?
- Yes, the conversion uses the US gallon of about 3.785 L. Imperial-gallon MPG figures are numerically higher.
