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

What this converter does

Kilometres per litre is how a lot of the world rates fuel economy, but if you are used to UK miles per gallon, the metric figure needs translating. This converter takes a km/L figure and gives you UK mpg. Enter the km/L value and read off the mpg, so a metric economy figure makes sense in British terms.

The conversion factor

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

mpg (UK) = km/L × 2.82481

That factor folds together litres into UK gallons and kilometres into miles. It is a larger number than the one used for US mpg, which is the detail to keep in mind, since the result comes out in Imperial-gallon terms.

Why the UK figure runs high

The UK gallon is about 4.546 litres, bigger than the US gallon's 3.785 litres, so a car covers more miles on one. That means the same km/L figure turns into a higher number in UK mpg than it would in US mpg, by around 20 percent. So if you convert a km/L value and the mpg looks generous, that is the Imperial gallon at work, not an unusually thrifty car. It is the same reason British economy figures always look healthier than American ones for the very same vehicle.

A worked example

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

• 18 × 2.82481 = 50.8 mpg (UK)

So 18 km/L is about 50.8 UK mpg. The same 18 km/L would be roughly 42 mpg in US terms, and the gap between those two figures is purely the gallon. In UK terms, this is a genuinely economical car.

Common km/L values in mpg (UK)

As anchors, 15 km/L is about 42.4 mpg UK, and 20 km/L comes out near 56.5 mpg UK.

Where you would use it

This is for a UK mpg thinker reading a km/L figure. Cars in many markets, especially across Asia, are rated in km/L, so converting lets you judge them against the UK numbers you know. It helps when researching a model sold in several countries, when a metric review quotes km/L, or when comparing a locally rated car with British figures. Just remember the answer is in Imperial-gallon mpg, which is why it reads higher than the US equivalent of the same km/L.

Questions people ask

How do I convert km/L to UK mpg?

Multiply the km/L figure by 2.82481. The factor combines the litre-to-UK-gallon and kilometre-to-mile conversions.

Why is UK mpg higher than US mpg for the same km/L?

The UK gallon is larger, so a car travels further on one. The same km/L therefore converts to a higher number in UK mpg than in US mpg, by about 20 percent.

What is 18 km/L in UK mpg?

About 50.8 mpg, a genuinely economical figure in Imperial-gallon terms.

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