Costco Fuel Savings Calculator
Work out whether a Costco (or similar warehouse club) membership pays for itself just from cheaper fuel — after the cost of the detour to get there and back.
Estimate only. Figures are illustrative — membership prices, fuel-price gaps and your own mileage all change. Check current terms at costco.co.uk before joining.
Not worth it on fuel alone
£9 Net loss per year
- Fuel you'll buy in a year
- 841 litres
- Gross fuel saving
- £34
- Membership fee
- £37
- Detour fuel cost
- £7
- Net loss
- £9
Buy about 1,077.3 litres (9,478.9 miles' worth) at the warehouse in a year to cover the fee and detour
Things to weigh up
- Costco only has around 20 UK warehouses with a fuel station attached, so check one is genuinely on your regular route before joining for this alone.
- Fuel is rarely the only reason to join — stack this saving with bulk grocery and household discounts using our Warehouse Membership calculator for the full picture.
- A second car, or a partner who also drives, spreads the same membership fee across more fuel purchases and improves the maths fast.
- Warehouse fuel stations are usually card/contactless only with no loyalty scheme of their own — factor that out of any other fuel-loyalty comparison.
How this is worked out
We convert your annual mileage into litres using your mpg (1 UK gallon = 4.54609 litres exactly), then multiply by the pence-per-litre saving you'd get at the warehouse versus your usual station. From that gross saving we subtract the membership fee and the fuel cost of the extra detour miles you'd drive, per fill, to actually get there — what's left is your real net saving. The break-even figure shows how many litres (and the equivalent miles) you'd need to buy at the warehouse in a year just to cover the fee and the detour, before you're saving anything at all.