How to work out the fuel cost of a van trip.

UK fuel is sold in litres but vehicles are measured in miles per gallon. Here is the conversion, and a quick way to price fuel into a trip.

The conversion

A UK (imperial) gallon is 4.54609 litres. Litres per mile = 4.54609 ÷ mpg. Do not use the US gallon figure, because it gives the wrong answer for UK mpg.

The formula

Fuel cost = miles ÷ mpg × 4.54609 × price per litre

Worked example (illustrative)

A 120-mile trip at 35 mpg uses 120 ÷ 35 × 4.54609 ≈ 15.6 litres. At £1.50 a litre the fuel costs about £23.38, or roughly 19.5p a mile.

Things that change your real mpg

• Load weight and roof racks
• Stop-start city driving versus steady motorway speed
• Tyre pressure and servicing
• Using the manufacturer's quoted mpg instead of your own figure. Track your real mpg over a few tanks.

Open the free fuel cost calculator

Common questions

Is fuel the biggest cost of running a van?

It is often the largest variable cost, but fixed costs can be larger overall. See the cost per mile guide.

Related guides

• ULEZ and Congestion Charge cost for a van delivery
• Van cost per mile in the UK
• Is a delivery job worth taking?

All guides · All free calculators

Figures are examples and the charge rates were checked in October 2026. Rates, hours and rules change, so confirm them with Transport for London or the relevant authority before you rely on them. This is general guidance, not legal or financial advice.