How do I convert L/100km to MPG?

Use the formula MPG = 235.215 / (L/100km). For example, 8 L/100km is about 29.4 MPG (US). This tool does the conversion for you.

How do I estimate trip fuel cost?

Multiply the distance by your consumption (L/100km), divide by 100 to get litres used, then multiply by the fuel price per litre.

Fuel Economy Calculator — MPG & L/100km

Fuel economy

Distance (km) Fuel used (litres)

L/100km—

MPG (US)—

MPG (UK)—

Trip cost

Fuel price ($/litre)

Trip cost—

Understand your car's real fuel cost

Fuel economy is reported differently around the world: North America uses miles per gallon, Europe uses litres per 100 kilometres, and the two numbers are not interchangeable at a glance. This calculator bridges that gap. Enter a distance and the fuel you used, and you get your consumption in L/100km, US MPG, and UK MPG all at once.

The trip cost section turns that figure into money. Set your local fuel price and the tool multiplies your consumption by the distance to tell you exactly what a journey will cost before you set off. Because it runs locally in your browser, it works on the road even when the signal drops.

Add this page to your home screen and keep a fuel calculator in your pocket for every fill-up.

Frequently asked questions

What is a good L/100km figure?

Most modern petrol cars sit between 6 and 9 L/100km. Hybrids and diesels are often lower.

Why are US and UK MPG different?

A US gallon is smaller (3.785 L) than a UK imperial gallon (4.546 L), so the same car shows a higher MPG in the UK.

Does this work offline?

Yes, it runs entirely in your browser.