Fuel Consumption Converter – MPG to L/100km in 3 Easy Steps
Fuel Consumption Converter
Use this fuel consumption converter: type a value into any field to instantly convert across all fuel economy and consumption metrics.
Use this free fuel consumption converter to switch between litres per 100 km, US miles per gallon, UK (imperial) miles per gallon and kilometres per litre. Type a value into any box and the other three update instantly, handling the inverse maths for you.
Quick answer
L/100km = 235.215 ÷ US MPG, and US MPG = 235.215 ÷ L/100km. For UK MPG, use 282.481 instead. 1 US MPG = 1.20095 UK MPG and 1 km/L = 2.35215 US MPG. So 30 US MPG = 7.84 L/100km = 36.0 UK MPG = 12.75 km/L, and 6 L/100km = 39.2 US MPG.
Table of Contents
Car makers, governments and drivers measure fuel economy in different ways. In the US and UK people talk about miles per gallon, but a UK gallon is bigger than a US gallon. Most of Europe, Canada and Australia use litres per 100 km, while many Asian countries use km per litre.
This fuel consumption converter puts all four units side by side so you can compare cars, reviews and spec sheets from any country.
Fuel Economy Conversion Formulas
- L/100km = 235.215 ÷ US MPG
- L/100km = 282.481 ÷ UK MPG
- UK MPG = US MPG × 1.20095
- km/L = US MPG × 0.425144
- km/L = 100 ÷ L/100km
MPG and km/L measure distance per fuel, so higher is better. L/100km measures fuel per distance, so lower is better.
US MPG to L/100km Chart
| US MPG | L/100km | UK MPG | km/L |
|---|---|---|---|
| 20 | 11.76 | 24.0 | 8.50 |
| 25 | 9.41 | 30.0 | 10.63 |
| 30 | 7.84 | 36.0 | 12.75 |
| 40 | 5.88 | 48.0 | 17.01 |
| 50 | 4.70 | 60.0 | 21.26 |
L/100km to MPG Chart
| L/100km | US MPG | UK MPG |
|---|---|---|
| 4 | 58.8 | 70.6 |
| 5 | 47.0 | 56.5 |
| 6 | 39.2 | 47.1 |
| 8 | 29.4 | 35.3 |
| 10 | 23.5 | 28.2 |
| 12 | 19.6 | 23.5 |
How to Use the Fuel Consumption Converter
Step 1: Enter US Miles Per Gallon
Type the figure in US Miles Per Gallon. A car rated at 30 US MPG uses 7.84 L/100km, which is 36.03 UK MPG and 12.75 km/L.
Step 2: Convert Litres per 100 km to MPG
Type in Liters per 100km to go the other way. A European rating of 6 L/100km equals 39.2 US MPG, 47.08 UK MPG and 16.67 km/L.
Step 3: Check the Reference Matrix
The Base Conversion Reference Matrix keeps the key constants in view: 235.21 for US MPG, 282.48 for UK MPG, 1.20095 between US and UK MPG and 2.35215 between km/L and US MPG. Press Clear Fields to reset.
Why UK MPG Is Higher Than US MPG
A UK imperial gallon is 4.546 litres, while a US gallon is 3.785 litres. The same car goes further on a bigger gallon, so its UK MPG figure is about 20% higher. Always check which gallon a review or advert uses before comparing cars.
Why L/100km Is Better for Comparing Savings
Because L/100km measures fuel used, savings add up in a straight line. Going from 10 to 8 L/100km saves 2 litres every 100 km. In MPG, going from 20 to 25 MPG saves more fuel than going from 40 to 50 MPG, even though both are a 5 MPG jump.
Working Out Trip Fuel Cost
Once you have L/100km, trip fuel is easy: litres = distance in km × L/100km ÷ 100. A 450 km trip in a car using 7.84 L/100km needs about 35.3 litres. Multiply by the fuel price per litre for the cost. Use the fuel consumption converter first if your car’s rating is in MPG.
Tips to Improve Fuel Economy
- Keep tyres at the recommended pressure.
- Drive smoothly and avoid hard acceleration.
- Remove roof racks and extra weight when not needed.
- Keep to steady speeds; fuel use rises quickly above about 100 km/h (62 mph).
- Service the engine and replace air filters on schedule.
More automotive tools: the Tire Size Calculator, the Bar to PSI Converter and the Length Converter.
Frequently Asked Questions
How do I convert MPG to L/100km?
Divide 235.215 by the US MPG figure. 30 MPG = 235.215 ÷ 30 = 7.84 L/100km.
What is 6 L/100km in MPG?
6 L/100km is about 39.2 US MPG or 47.1 UK MPG.
Is UK MPG the same as US MPG?
No. UK gallons are larger, so 1 US MPG equals about 1.2 UK MPG.
Is a lower L/100km better?
Yes. Lower L/100km means less fuel used per distance.
How do I convert km/L to L/100km?
Divide 100 by km/L. 12.5 km/L = 8 L/100km.
Is my data stored?
No. The fuel consumption converter runs in your browser and nothing is saved.