Kilometers per Liter to Miles per Gallon (US) Converter | km/L to mpg (US)

What this converter does

Kilometres per litre is a common way to quote fuel economy outside the US, but if you think in US miles per gallon, it does not give you an immediate feel. This converter takes a km/L figure and turns it into US mpg. Enter the km/L value and read off the mpg, so a metric economy figure lands in American terms.

The conversion factor

To go from kilometres per litre to US mpg you multiply:

mpg (US) = km/L × 2.35215

That factor is the inverse of the US-mpg-to-km/L one, and it folds together litres into US gallons and kilometres into miles. The result is in US mpg, using the US gallon of about 3.785 litres, so it will read higher than the same car would in UK mpg.

Both run the same way

One thing that keeps this easy: kilometres per litre and miles per gallon both measure distance per unit of fuel, so a higher number is the better car in either. Converting between them is purely a change of units, with no flip in meaning. It is worth holding onto, because the other common metric figure, litres per 100 kilometres, runs the opposite way, where a lower number is better. Kilometres per litre is the metric measure that behaves like mpg.

A worked example

Say a car is rated at 18 km/L and you want that in US mpg.

• 18 × 2.35215 = 42.3 mpg (US)

So 18 km/L is about 42.3 US mpg, a genuinely economical figure for a petrol car. Putting it in mpg lets an American reader feel straight away that this is an efficient car, in the unit their instinct is tuned to.

Common km/L values in mpg (US)

As anchors, 10 km/L is about 23.5 mpg US, and 15 km/L comes out near 35 mpg US.

Where you would use it

This is for an mpg thinker reading a km/L figure. Cars in many markets, particularly across Asia, are rated in km/L, so converting lets you judge them against the US mpg numbers you know. It helps when researching a model sold in several countries, when a metric review quotes km/L, or when lining a locally rated car up against US figures. Because both units run the same way, the comparison is direct once you have converted.

Questions people ask

How do I convert km/L to US mpg?

Multiply the km/L figure by 2.35215. The factor combines the litre-to-US-gallon and kilometre-to-mile conversions.

Is the result in US or UK mpg?

US mpg, based on the US gallon of about 3.785 litres. The same km/L figure would give a higher number in UK mpg.

What is 15 km/L in US mpg?

About 35.3 mpg. It is a handy anchor for a reasonably economical petrol car.

References

1. National Institute of Standards and Technology (NIST), Special Publication 811, Guide for the Use of the International System of Units (gallon definitions and unit conversions). https://www.nist.gov/pml/special-publication-811
2. U.S. Department of Energy and EPA, fueleconomy.gov (fuel economy ratings and information). https://www.fueleconomy.gov/