About CheapFuel
CheapFuel is a set of free, no-nonsense tools for spending less at the pump — the real cost of a trip, fuel-economy conversions, what a tank costs to fill, and guides that rank money-saving changes by how much they actually save.
How the calculators work
Every figure runs through one shared set of conversions, so the maths is consistent across the site. We convert all inputs to canonical units before calculating:
- Fuel economy → litres per 100 km
- Price → price per litre
- Distance → kilometres; volume → litres
Conversions use the exact internationally-agreed definitions: 1 imperial gallon = 4.54609 L, 1 US gallon = 3.785411784 L, and 1 mile = 1.609344 km. That’s why UK and US MPG never get mixed up.
Accuracy & honesty
The calculators are precise, but they can only be as accurate as the numbers you put in. Official fuel-economy figures are measured in ideal conditions; real-world consumption is typically 10–30% higher depending on driving style, weather, load and traffic. For the best results, use your own measured economy. All results are estimates for general guidance — they are not financial advice.
What’s next
We’re building a live station price finder so you can see the cheapest fuel near you in real time, plus a companion mobile app. The calculators here are the foundation.
Last reviewed June 2026.
Cheapest fuel near you, in your pocket.
Everything on this site, plus live station prices near you, price-drop alerts and a fill-up log that tracks your real running costs over time.
- Live station prices
- Price-drop alerts
- Fill-up log