Work out your vehicle’s fuel efficiency in seconds. Enter the distance you travelled and the fuel you used to get MPG or litres per 100 km — a quick way to track running costs and compare cars.
For the most accurate figure, fill the tank completely, reset the trip meter, then refill and note how much fuel went in.
How to Use
- Choose your unit system — UK, US or metric.
- Enter the distance you travelled.
- Enter how much fuel you used over that distance.
- Read your fuel efficiency instantly, with handy equivalents.
Key Features
- MPG for UK and US gallons, or litres per 100 km.
- Automatic equivalents so you can compare any figures.
- Labels switch units to match your chosen system.
- Live recalculation as you type.
- Private — everything runs in your browser.
FAQs
What is a good MPG figure?
It depends on the car, but as a rough guide: under 30 MPG (UK) is thirsty, 40–50 is respectable for a petrol car, and 60+ is excellent — typical of efficient diesels and hybrids.
What is the difference between UK and US gallons?
A UK gallon is 4.546 litres while a US gallon is 3.785 litres, so the same car shows a higher MPG number in the UK system. Pick the system that matches your country.
How can I improve my fuel efficiency?
Drive smoothly, keep tyres at the right pressure, remove roof boxes when not needed, service the car regularly and avoid idling for long periods.
Is L/100km better than MPG?
Neither is better — they are just different conventions. L/100km has the advantage that fuel cost scales directly with the number, while MPG is the familiar figure in the UK and US.
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