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Motor Vehicle Fuel Consumption Unit Conversion Calculator

economy sports carConvert between European (metric), British and American motor vehicle fuel consumption measures: US MPG : Imperial MPG : Litres/100km.

Including Fuel Consumption Calculator (below) - which takes the amount of gasoline (petrol), diesel or gas (LPG/methane) added and the distance you driven (with optional fuel cost calculator to show cost per mile or kilometer in US Dollars, British Pounds and Euros).

Convert Your Fuel Consumption

This calculator converts between various measures of fuel consumption of motor vehicles:

Choose the measure that you are converting from:


There are 1.200949857 US gallons to 1 Imperial (UK) gallon (US gallons are smaller). Therefore 20 miles per US gallon (less fuel) is more economical than 20 miles per imperial (UK) gallon (more fuel).

Fuel Consumption Calculator

Use this too if you know your distance and amount of fuel (and optionally your spending) and want to work out the fuel consumption that you achieved.

The best way to use this tool is: (a) Top up your fuel tank and zero your trip meter. (b) Make a trip in your car. (c) Top up your tank again, recording the amount of fuel added and the distance shown on your trip meter.

Choose the unit of volume for the fuel:

Choose the units of distance for the distance covered:

Tripmeters/odometers are inaccurate e.g. yours may show 100 miles when only 99.6 miles have been completed. That example would require a correction factor of 1.004 (100 divided by 99.6), which is 1.004, showing that you used less fuel per unit of distance than without correction. * Leave as 1.000 unless you have experimentally calculated your vehicle's correction factor and understand variation due to tyre inflation pressure and wear. If you wish to correct for refuelling measurement inaccuracy, incorporate that into the tripmeter correction factor.

Include Costs? (Optional)

Choose your currency:

Enter your cost per unit volume or for this tank fill:


(results below...)


Fuel Consumption:

Cost per mile or kilometer driven: (if costs were entered)


This converter and calculator can help your tailor your driving technique to ensure cost effective motoring. It works fine for cars and motorbikes as well as for other vehicles.

I initially created this page in 2006 to aid discussion of the fuel economy of my classic Range Rover on an online forum.

Contact Me

How and why do you use this page? Do you compare your different cars? Do you discuss your vehicle's fuel consumption with people from different countries?

© Mark Porthouse 2016