UK Fuel Costs: How to Price a Short Journey

Business & Money Desk 2026-10-17 07:35 Updated: 10:40 4 min read

Vintage style petrol station pumps standing in front of a British commercial garage.

A short journey’s fuel cost depends on three things: the distance, your vehicle’s miles per gallon (mpg), and the price you pay at the pump. Use a local forecourt price for a personal estimate; the UK government’s weekly figures are a national benchmark, not a quote for a particular station.

Calculate fuel cost from distance, mpg and pump price

First estimate how many litres the journey uses. Divide the distance in miles by your vehicle’s miles per gallon, then convert UK gallons to litres. A UK imperial gallon contains about 4.546 litres.

Fuel used (litres) = distance (miles) ÷ mpg × 4.546

Then multiply the litres by the pump price per litre, expressed in pounds. If the price is shown in pence, divide it by 100 first.

Journey fuel cost (£) = fuel used (litres) × price per litre (£)

For a quick combined calculation:

Cost (£) = distance (miles) ÷ mpg × 4.546 × price per litre (£)

This estimates fuel consumed on the journey. It does not include parking, tolls, vehicle wear or other travel costs.

Worked example: a 20-mile trip in a 40 mpg car

Suppose a car averages 40 mpg and the trip is 20 miles. It would use an estimated 2.27 litres: 20 ÷ 40 × 4.546.

To finish the estimate, multiply 2.27 by the price per litre at the station you expect to use. For illustration only, if that price were 1.50 pounds per litre, the fuel would cost about £3.41. That example price is not a current UK average or a live station quote.

UK Fuel Costs: How to Price a Short Journey

For a return trip, double the distance if the route back is similar. If the return route differs, calculate each leg separately. Round the final amount to the nearest penny for budgeting, while remembering that actual consumption can vary.

Use your car’s real-world mpg where possible

The mpg figure makes a substantial difference to the estimate. A vehicle’s official or advertised figure may not match everyday driving, so use a figure based on your own fuel use if you have one. If you only have a vehicle handbook or dashboard estimate, treat the result as approximate.

Fuel consumption can change with traffic, speed, hills, weather, load, tyre condition and driving style. Stop-start urban traffic may use more fuel than a steady-speed trip of the same distance. A planned journey cost is therefore a budgeting guide, not a guaranteed amount.

Check that the mpg figure is for UK gallons. Some sources use US gallons, which are smaller; using a US mpg figure in the formula above would give a misleading result unless converted first.

Compare the national benchmark with nearby forecourts

The Department for Energy Security and Net Zero publishes UK road fuel price data and related petroleum product price statistics. See the government’s road fuel and petroleum product prices collection for the latest available official data.

A national average helps show a broad benchmark for petrol or diesel. It cannot tell you the price at a specific pump: prices can differ between towns, retailers and individual forecourts, and the government’s weekly data may not reflect a change made after its reporting period.

To estimate your own trip, compare prices at stations near your starting point, destination or route. Use the same fuel type, check when each local price was reported, and use the price per litre shown by the station or a reliable current local listing. Then put that price into the calculation above. If you are checking a station in person, the pump display is the price you will pay there.

What can change the amount you spend?

Your result is only as useful as its inputs. Recalculate if you switch between petrol and diesel, choose a different route, expect heavy traffic, or plan to refuel at a station with a different price. For a recurring commute, estimate a typical one-way trip and multiply by the number of journeys, then allow for variation in traffic and pump prices.

The government data provides a consistent national reference, while a local pump price makes the estimate relevant to your journey. Check the latest dataset and the nearby station price before travelling if you need a tighter household budget figure.

Source: UK Government, Department for Energy Security and Net Zero

Context & actions About this article

Source check Calculation method

The worked example shows how to estimate fuel spending using distance, UK mpg and a pump price; its sample price is not a current quote.

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