What is a good L/100km figure?

For a modern petrol car, 5-7 L/100km is considered good (equivalent to 40-56 UK mpg). Diesel cars typically achieve 4-6 L/100km. Small city cars can manage under 5 L/100km, while large SUVs may use 10-14 L/100km.

How do I convert UK MPG to L/100km?

Divide 282.481 by your UK MPG. For example, 45 mpg = 282.481 / 45 = 6.3 L/100km. Note: this uses the UK imperial gallon (4.546 litres), not the smaller US gallon.

Why does Europe use L/100km instead of MPG?

L/100km tells you how much fuel you use for a set distance, making it easier to calculate journey costs. Lower numbers are better. It is also a linear scale, unlike MPG where the difference between 10 and 20 mpg is much larger than between 40 and 50 mpg.

What is the conversion factor for UK MPG to L/100km?

The conversion factor is 282.481. Divide 282.481 by the UK MPG figure to get L/100km, or divide 282.481 by L/100km to get UK MPG. This factor comes from the UK imperial gallon (4.54609 litres) and the miles-to-kilometres conversion (1.60934).

Why is L/100km a more honest measure of fuel economy?

MPG is a hyperbolic scale where improvements at the low end save more fuel than at the high end. Going from 15 to 20 mpg saves far more fuel than going from 45 to 50 mpg. L/100km is linear, so a 1 L/100km improvement always saves the same amount of fuel regardless of the starting point.

CarCalcs

Litres Per 100km Calculator

Convert your fuel consumption to the European L/100km standard or convert from UK MPG.

Input Method

Fuel Used

Distance Driven

How We Calculate This

This calculator converts between the UK MPG system and the European litres per 100km standard.

The Formulas

L/100km from distance = (Litres used / km driven) x 100
L/100km from UK MPG = 282.481 / MPG
UK MPG from L/100km = 282.481 / L/100km
US MPG from L/100km = 235.215 / L/100km

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.