Supermarket Fuel Comparison Calculator
Compare two petrol stations and see whether driving to the cheaper one is actually worth it, once the fuel cost of getting there is taken into account.
Estimate only. Fuel prices change daily and vary by station and region, treat these figures as illustrative. Check current local prices before deciding where to fill up.
Enter both stations' prices
Add the price at each station, the detour distance and your mpg to see if the trip is worth it.
Why the 'obvious' saving can be a loss
Multiplying the pence-per-litre gap by your tank size looks like free money, but getting to the cheaper station and back also costs fuel. We convert your one-way detour distance into a return trip, work out how many litres that burns at your mpg (1 UK gallon = 4.54609 litres exactly), and price it at your usual station's rate. Subtract that from the pump-price saving and you get the real, net saving, which can easily turn negative on a short fill with a long detour.