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Fuel Economy Calculator

Enter one fuel-economy measure and convert it instantly to L/100 km, km/L, US MPG and Imperial MPG.

Convert fuel economy units

Enter one fuel-economy measure and convert it instantly to L/100 km, km/L, US MPG and Imperial MPG.

L/100 km—
km/L—
MPG (US)—
MPG (Imperial)—

Fuel economy calculator and converter

This fuel economy calculator converts between the four units drivers most often encounter. L/100 km measures fuel consumed for a fixed distance, while km/L and MPG measure distance travelled for a fixed amount of fuel. Because one is an inverse measure of the others, doubling km/L does not simply double L/100 km.

US MPG vs Imperial MPG

A US gallon and an Imperial gallon are different volumes. That means the same vehicle produces a higher numerical Imperial MPG than US MPG. The converter uses standard litre-per-gallon conversion constants so the two values remain distinct.

Real-world fuel economy

Official test-cycle fuel economy and actual road consumption can differ because of traffic, speed, temperature, load, tyre pressure, driving style and accessory use. For running-cost planning, use an observed average from several fill-ups when possible.

How to use the result

Enter the unit shown on a dashboard, listing or specification sheet, then compare the equivalent units. The L/100 km value is particularly useful when calculating fuel cost over a known distance.

Frequently asked questions

How do I convert L/100 km to km/L?
Divide 100 by the L/100 km value.
Why is Imperial MPG higher than US MPG?
An Imperial gallon is larger than a US gallon, so the same fuel consumption produces a higher Imperial MPG number.
Which fuel economy unit is better?
None is inherently better; use the unit standard in your market and keep the unit consistent when comparing vehicles.
Does this estimate real-world mileage?
It converts an entered value. Real-world fuel economy depends on operating conditions and the value you supply.