MPG to L/100km Converter
Convert miles per gallon, litres per 100 km, km per litre, gallons per 100 miles and miles per litre in any direction, with separate US and imperial gallons. Free, instant, and every calculation runs in your browser.
1 mpg (US) = 235.21 L/100km
These two scales run in opposite directions: a higher number on one side means a lower number on the other.
Need your own figure from a fill-up? Use the miles per gallon calculator.
Every converter
Each page has its own explanation, formula, worked example and table. Pick the direction you need.
- MPG to L/100km1 mpg (US) = 235.21 L/100km
- L/100km to MPG1 L/100km = 235.21 mpg (US)
- MPG to km/L1 mpg (US) = 0.4251 km/L
- km/L to MPG1 km/L = 2.35 mpg (US)
- MPG (UK) to L/100km1 mpg (UK) = 282.48 L/100km
- MPG (US) to MPG (UK)1 mpg (US) = 1.20 mpg (UK)
- Kilometres to Miles1 km = 0.6214 mi
- Miles to Kilometres1 mi = 1.61 km
- Gallons to Litres1 gal (US) = 3.79 L
- Litres to Gallons1 L = 0.2642 gal (US)
- MPG CalculatorMiles and fuel from a fill-up to mpg, L/100km and km/L
- Fuel Cost CalculatorTrip or yearly fuel cost from distance, economy and price, with CO2
How fuel economy units work
There are two ways to state how efficient a car is. Distance per fuel, which is miles per gallon or kilometres per litre: higher is better. Fuel per distance, which is litres per 100 km: lower is better. They are reciprocals of each other, so converting between them is a division rather than a multiplication, and the MPG or L/100km guide explains why that changes how you should compare cars.
The complication is the gallon. The US gallon is exactly 3.785411784 litres and the imperial gallon used in Britain is exactly 4.54609 litres, a fifth larger. The same car therefore has two mpg figures that differ by 20.095%, and any converter that does not ask which gallon you mean is guessing. Every converter here has a US/UK switch, and the gallon guide covers where the two came from.
The mile is exactly 1.609344 km. From those three definitions every constant on this site follows: 235.214583 for mpg (US) to L/100km, 282.480936 for mpg (UK), 0.425144 km/L per mpg (US). The maths lives in one tested module and every page reads from it, so a figure in a table here will always match the converter beside it.
Guides
- US vs UK Gallon: Why the Same MPG Means Different ThingsThe imperial gallon is 4.54609 litres, the US gallon 3.785411784: a 20.095% gap that changes every mpg figure. Where the two came from and how to convert.
- Understanding Fuel Economy Ratings: EPA, WLTP, NEDC and What They MeasureWhat the EPA, WLTP, NEDC, WLTC and ARAI fuel economy tests actually measure, why their figures differ for the same car, and how to compare one with another.
- MPG or L/100km: Why Two Systems Exist and Which Is ClearerMPG measures distance per fuel, L/100km fuel per distance. They are reciprocals, which changes how car comparisons look. Why both exist and which one is honest.
- How to Calculate Your Real Fuel Economy by HandThe fill-to-fill method for measuring real fuel economy: what to record, the sums in mpg, L/100km and km/L, and the mistakes that make a result meaningless.
- What Counts as Good Fuel Economy in 2026Realistic 2026 fuel economy benchmarks by type of car, in mpg (US and UK), L/100km and km/L, with the test behind each figure explained so you can judge any number.
- Why Your Real-World MPG Never Matches the Official FigureOfficial mpg comes from a lab cycle; your driving does not. The size of the gap, what causes it, which cars fall furthest short, and how to predict your own figure.
- How to Improve Your Fuel EconomyWays to improve fuel economy ranked by how much each saves: driving style, speed, trip planning, weight, roof racks, idling and maintenance. Numbers, no gadgets.
- How Many Miles Will a Gallon of Gas Get You?A gallon of gas takes a typical car 20 to 35 miles, a hybrid 50 or more, a pickup under 20. Figures by type of car, how to work out yours, and the metric view.
Frequently asked questions
- How do I convert MPG to L/100km?
- Divide 235.214583 by the mpg figure for US gallons, or 282.480936 by it for imperial (UK) gallons. 30 mpg (US) is 7.84 L/100km. The converter above does it as you type, and the MPG to L/100km page has the formula, examples and a table.
- How many miles per gallon of gas does a car get?
- A typical new car gets 25 to 35 miles on one US gallon, a small hybrid 50 or more, and a full-size pickup 18 to 23. The guide on miles per gallon of gas gives figures by type of car and explains how to work out your own.
- Why are US and UK mpg figures different?
- Because the gallons are different sizes. A US gallon is 3.785411784 litres and an imperial gallon is 4.54609 litres, 20.095% larger, so the same car goes 20% further per imperial gallon. 40 mpg (US) is 48 mpg (UK). The US vs UK gallon guide explains it in full.
- Is lower or higher L/100km better?
- Lower. L/100km is fuel used per fixed distance, so a smaller number means a more efficient car. MPG and km/L measure distance per fuel, so higher is better on those.
- What is the difference between km/L and L/100km?
- They are reciprocals. km/L is 100 divided by L/100km: 20 km/L is 5 L/100km. km/L is used in Japan, India and Brazil; L/100km in Europe, Canada and Australia.
- Does the site store what I type?
- No. Every conversion runs in your browser. Nothing you enter is sent to a server, and there is no account, sign-up or limit.