Fuel Efficiency Converter

Convert between miles per gallon (mpg), liters per 100km (L/100km), and kilometers per liter (km/L).

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1. Select the fuel efficiency unit you want to convert from (mpg, L/100km, or km/L). 2. Enter your vehicle fuel efficiency value in the input field. 3. See the equivalent fuel economy in all three standards calculated instantly. 4. Compare international vehicle specifications by converting between regional fuel economy formats. 5. Copy the converted fuel efficiency value to use in vehicle comparisons or trip planning.

About This Tool

The Fuel Efficiency Converter helps you convert between the three most common fuel economy measurement standards used worldwide. Whether you are comparing vehicle specifications from different countries, calculating travel fuel costs, or shopping for a fuel-efficient car, this tool makes it easy to understand fuel economy in any format.

Our converter handles miles per gallon (mpg) used primarily in the US and UK, liters per 100 kilometers (L/100km) used throughout Europe and much of the world, and kilometers per liter (km/L) common in parts of Asia and South America. Unlike most unit conversions, fuel efficiency conversion involves an inverse relationship - higher mpg means lower L/100km - which makes manual conversion error-prone.

Fuel efficiency comparison is essential when evaluating vehicles from international manufacturers, planning road trips abroad, or understanding environmental impact ratings. A car listed at 7.5 L/100km in a European review might not mean much to someone used to thinking in mpg. This converter instantly bridges that gap so you can compare fuel economy numbers from any source.

Formula / How It Works

mpg (US) to L/100km: divide 235.215 by mpg | mpg to km/L: multiply mpg by 0.425144 | L/100km to km/L: divide 100 by L/100km

Frequently Asked Questions

To convert mpg (US) to L/100km, divide 235.215 by the mpg value. For example, 30 mpg equals approximately 7.84 L/100km. Note that this is an inverse relationship - higher mpg means lower L/100km.
For conventional gasoline cars, good fuel efficiency is roughly 30-40 mpg (7.8-5.9 L/100km). Hybrids typically achieve 40-60 mpg (5.9-3.9 L/100km). Electric vehicles are rated differently, often in MPGe (miles per gallon equivalent).
Europe uses L/100km because it directly tells you how much fuel you will use for a given distance, making cost calculations straightforward. MPG tells you how far you can go on a set amount of fuel. Both communicate efficiency, just from different perspectives.
US mpg and UK (imperial) mpg differ because the US gallon (3.785 liters) is smaller than the imperial gallon (4.546 liters). A car rated at 30 US mpg would be rated at about 36 UK mpg. Our converter uses US gallons by default.

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