Easily calculate your vehicle's fuel efficiency, track your costs, and save money on every journey.
An MPG calculator is a fuel-efficiency tool that works out how many miles your car travels per gallon of fuel. Enter distance and fuel used, and it returns your real-world MPG so you can measure performance, compare journeys, and spot changes in running costs over time.
UK drivers often see different figures online because UK gallons (4.546 litres) are larger than US gallons (3.785 litres). For the same trip, UK MPG looks higher. Use this calculator to keep units consistent, compare like-for-like results, and link MPG directly to UK fuel prices.
Enter the mile driven for this trip.
Enter how much fuel you used.
Optional: add pence per litre to estimate journey cost.
Calculating MPG (miles per gallon) is a simple process that involves a few steps. Here's how to do it:
Begin by filling up your vehicle's fuel tank completely until the pump clicks off.
Reset your vehicle's trip odometer to zero to track the miles for this specific calculation.
Drive as you normally would until you need fuel again. Try to use your regular routes.
Fill up your tank again. Note the miles driven on your trip odometer and the exact amount of fuel added.
Most UK cars return somewhere between 35 and 55 MPG in real-world driving — noticeably lower than the official laboratory figures quoted in brochures. Typical ranges by fuel type:
| Car / fuel type | Typical real-world MPG |
|---|---|
| Small petrol hatchback | 45–55 MPG |
| Family petrol car | 35–45 MPG |
| Diesel (hatchback or saloon) | 45–60 MPG |
| Hybrid | 50–65 MPG |
| SUV or larger petrol car | 25–40 MPG |
These are real-world figures, not manufacturer claims — driving style, journey length, load and even tyre pressure move them by 10–20%. Work out where your own car sits by entering your last fill-up above, or read our full guide to what counts as a good MPG and see the most fuel-efficient cars in the UK.