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What is in a litre of fuel?
Type in a pump price and see how much of it is fuel duty, how much is VAT, and how much is left for the fuel itself and the retailer.
Prices prefilled from the official Fuel Finder data, updated 28 August 2026. Change any box and the answer updates as you type.
The three parts of the price
Every litre you buy carries two taxes. Fuel duty is a fixed amount per litre, the same whatever the pump price. VAT is charged at 20 percent on top of everything else, which means one sixth of the final pump price is VAT. What is left after both taxes is the cost of the fuel itself, the cost of getting it to the forecourt, and the retailer's margin.
Because duty is a fixed sum, the tax share of the price is highest when fuel is cheap and lowest when it is dear. At today's typical price well over half of what you pay at the pump is tax. Our fuel duty guide covers the rate and the changes already announced for 2027, which you can switch between above.
What the retailer actually keeps
The remaining part is often misread as profit. It is not. It has to cover the wholesale cost of the refined fuel, which tracks the oil price and the pound, plus transport, the running of the forecourt and only then a margin. That margin is usually a few pence a litre, which is exactly why a forecourt that is a few pence cheaper is giving away a large share of what it keeps. Supermarkets can do that because fuel brings people to the shop, as our guide on why supermarket fuel is cheaper explains.
Common questions
How much of petrol price is tax?
At today's typical price well over half. Fuel duty is a fixed amount per litre and VAT is one sixth of the final pump price. Enter a price above and the calculator shows the exact split.
What is fuel duty?
A fixed tax per litre of petrol and diesel, charged before VAT. It is the same number of pence whatever the pump price, so it makes up a bigger share of the price when fuel is cheap than when it is expensive.
How much do petrol stations make per litre?
Only a few pence. After duty, VAT, the wholesale cost of the fuel and delivery, the retailer's margin on a litre is small, which is why a forecourt a few pence cheaper is giving away a large share of what it keeps.