Fuel Economy Converter

What This Converter Does

The tricky thing about fuel economy is that the units run in opposite directions. Miles per gallon and km per litre measure distance per fuel, so bigger is better. But litres per 100 km measures fuel per distance, so smaller is better. That is why you cannot just multiply by one factor to swap between them - going up in one means going down in another.

Enter a value in any of the three and the tool shows all three at once, flipping the relationship correctly for you.

How It Works

$$\text{L/100km} = \frac{235.215}{\text{MPG}} \qquad \text{km/L} = \frac{100}{\text{L/100km}}$$

Note that MPG and km/L measure distance per fuel (higher is better), while L/100km measures fuel per distance (lower is better) — so they move in opposite directions.

How to Use It

1. Enter the value.
2. Choose the unit it is in.
3. Read all three measures.

Worked Examples

Input	MPG	L/100km	km/L
30 MPG	30	7.84	12.76
40 MPG	40	5.88	17.01
8 L/100km	29.4	8	12.5

FAQ

How do you convert MPG to L/100km?

Divide 235.215 by the MPG. So 30 MPG is about 7.84 L/100km. They are inverse measures.

Why is the relationship inverse?

MPG is distance per unit of fuel, while L/100km is fuel per unit of distance, so a higher MPG means a lower L/100km.