What is the formula to convert MPG (UK) to L/100km?

L/100km = 282.481 ÷ MPG (UK). The constant 282.481 comes from the number of liters in a UK (imperial) gallon (4.54609) multiplied by the meters per mile (1609.344), divided by 1000. For example, 40 MPG (UK) converts to 282.481 ÷ 40 = 7.06 L/100km.

Why is the relationship between MPG and L/100km inverse?

MPG measures distance traveled per unit of fuel, while L/100km measures fuel consumed per unit of distance. A higher MPG means better efficiency, but a lower L/100km also means better efficiency. The two scales move in opposite directions.

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

MPG (UK) = 282.481 ÷ L/100km. For example, 7 L/100km converts to 282.481 ÷ 7 = 40.35 MPG (UK).

What is the difference between UK MPG and US MPG?

The UK (imperial) gallon is larger than the US gallon — 4.54609 L vs 3.785411784 L. This means the same vehicle will show a higher MPG figure in the UK than in the US. The conversion constant for UK MPG to L/100km is 282.481, while for US MPG it is 235.215.

What is 50 MPG (UK) in L/100km?

50 MPG (UK) = 282.481 ÷ 50 = 5.65 L/100km. This is a typical figure for a fuel-efficient petrol or diesel car in the UK.

MPG (UK) to L/100km Converter

Name: MPG (UK) to L/100km Converter
Availability: InStock
Author: Nham Vu

Enter UK MPG to get L/100km instantly — or enter L/100km to convert back. Includes a reference table for common UK fuel economy values.

Fuel Economy Converter

UK MPG (imperial miles per gallon)

= L/100km —

L/100km (liters per 100 km)

= UK MPG —

Formula: L/100km = 282.481 ÷ MPG (UK)

Reference Table

Click a row to load it into the converter.

MPG (UK)	L/100km	Typical vehicle

Summary

Enter UK MPG to get L/100km instantly — or enter L/100km to convert back. Includes a reference table for common UK fuel economy values.

How it works

Enter a fuel economy value in UK MPG in the top field.
The L/100km result appears instantly using the formula: L/100km = 282.481 ÷ MPG (UK).
Use the reverse field to convert L/100km back to UK MPG.
Click "Copy" next to any result to copy it to your clipboard.
Click any row in the reference table to load that value into the converter.

Use cases

Convert a UK car listing MPG figure to the European L/100km standard.
Compare fuel economy between British and continental European vehicles.
Estimate fuel costs when driving in Europe using UK MPG specs.
Understand fuel efficiency ratings on UK-market cars.
Convert classic British car MPG figures to the modern L/100km metric.
Verify manufacturer efficiency claims across different regional standards.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu