How to compare petrol prices per litre
To compare petrol prices per litre, take the price difference between two stations in pence and multiply it by the number of litres you buy. A station that is 4p a litre cheaper saves you £2.00 on a 50-litre fill. Then take off the cost of any extra driving to get there. A fuel price checker does the comparing for you, as long as you check how recent each price is.
How are petrol prices shown in the UK?
UK forecourts show fuel prices in pence per litre, usually to a tenth of a penny, such as 159.9p. Standard unleaded (E10), super unleaded (E5) and diesel each have their own price, so make sure you are comparing the same fuel at each station.
The price includes fuel duty and VAT, so the number on the sign is what you pay. Duty and the VAT rate are the same at every station, so the gap between two forecourts comes down to each retailer's costs and pricing. Our guide to what makes up the price of petrol explains the parts.
How do I work out the cost of a fill-up?
Multiply the price per litre by the number of litres, then divide by 100 to get pounds.
- 45 litres at 159.9p is 45 × 159.9 = 7,195.5p, or about £71.96
- 50 litres at 159.9p is 50 × 159.9 = 7,995p, or £79.95
If you don't know how many litres your tank holds, check the owner's manual or your last receipt. Most drivers fill up before the tank is completely empty, so the litres you actually buy are usually less than the tank size.
What is the real difference between two stations?
The quick way is to multiply the price gap by the litres you buy. A gap of 1p a litre is worth 50p on a 50-litre fill. A gap of 6p is worth £3.00.
Small gaps add up over a year. If you fill up 50 litres every two weeks, that is 26 fill-ups and 1,300 litres a year. Saving 4p a litre on all of them is worth £52.00. These figures are an example, so use your own fill size and how often you fill up.
Is the cheapest petrol station always the cheapest?
No. A cheaper station further away only saves money if the saving on the fill is bigger than the fuel you burn getting there and back. This worked example uses made-up prices, not today's.
| Example | Station A | Station B |
|---|---|---|
| Price per litre | 165.9p | 159.9p |
| Cost of 50 litres | £82.95 | £79.95 |
| Extra round trip | None, it's on your route | 10 miles |
| Fuel for the extra trip at 35 mpg | £0.00 | About 1.3 litres, £2.08 |
| Total | £82.95 | £82.03 |
Station B is 6p a litre cheaper, which looks like a £3.00 saving. Once the drive is counted, the saving is 92p. If Station B were a few miles further away, Station A would win. Our guide to driving further for cheaper fuel has a rule of thumb you can use at the pump.
How do I know a price is up to date?
Check when it was reported. Under the government's Fuel Finder scheme, forecourts must report a price change within 30 minutes, but some report late or forget. A price reported this morning is more reliable than one from last week.
On this site, every price shows when the station reported it. We leave out prices that haven't been updated for 30 days, and we show the date on any price that is more than three days old. The pump price is always the one you pay, so check it before you fill up.
How do I use a fuel price checker?
Our fuel price checker uses the government's Fuel Finder data for 7,543 forecourts, refreshed twice a day. The latest prices were updated at 17:30 on 16 Oct.
- Search by postcode. Enter your postcode on the home page, or see an example for central Manchester. Choose your fuel.
- Pick a sort. Cheapest sorts by pump price. Nearest sorts by distance. Best value adds the fuel used for the round trip to the cost of a 50-litre fill, at about 35 mpg, and shows which station works out cheapest overall.
- Check the report time on the station you choose.
- Compare your town. Our town pages show local averages, the gap between the cheapest and dearest forecourts, and how nearby towns compare.
- Compare with the UK. The UK average is 174.2p for petrol and 199.2p for diesel. See the latest on our petrol prices and diesel prices pages.
Find the cheapest fuel near you
Prices change often, so a station that was cheapest last week may not be today. Search by postcode before you set off, and sign up for price alerts to get an email when fuel near you gets cheaper.
Sources
- GOV.UK: Drivers set to save as petrol prices launch on Google Maps (8 Oct 2026)
- GOV.UK: Fuel Finder guidance
- Live prices: the UK government's Fuel Finder scheme, via Cheapest Fuel. Contains public sector information licensed under the Open Government Licence v3.0.