UK driver calculator

MPG calculator

Calculate your real miles per gallon from miles driven and fuel added. You can also estimate litres per 100km, fuel cost and pence per mile.

Quick answer: UK MPG is usually calculated using imperial gallons. One UK gallon is 4.54609 litres. Real MPG can differ from dashboard MPG because of traffic, cold starts, tyre pressure, speed and driving style.

How to calculate MPG

Fill your tank, reset the trip counter, drive normally, then refill and note how many litres you added. Enter the miles driven and litres added here to estimate your real-world fuel economy.

Use this with other Driverz tools

After calculating your MPG, use it in the trip cost calculator to estimate journey costs, or compare it with your regular cost per mile.

Trip cost calculator Cost per mile tracker Find nearby fuel UK fuel guide All driver tools

MPG calculator FAQs

Is this UK or US MPG? This calculator uses UK imperial MPG. US gallons are smaller, so US MPG figures are not the same as UK MPG.
Why is my MPG lower than expected? Short journeys, cold weather, heavy traffic, under-inflated tyres, roof boxes and high motorway speeds can all reduce real-world MPG.
Should I use litres or gallons? UK pump fuel is sold in litres, so litres are usually easiest. If you already know the amount in UK gallons, you can select UK gallons instead.