How much is Diesel per Gallon?

Current Average Price

£8.02

Based on data from 30/03/2026

It's worth noting that fuel prices can vary across different regions and individual fuel stations due to factors such as competition and location. It is advisable to check with local petrol stations or use online price comparison tools for the most accurate and recent prices in your area.

How is the Diesel Price Per Gallon Calculated?

Like petrol, diesel in the UK is sold by the litre. To get the price per gallon, multiply the pence-per-litre price by 4.54609 — the number of litres in a UK Imperial gallon. So at 145p per litre, a gallon of diesel costs around £6.59.

Diesel is typically priced a few pence per litre above petrol at UK forecourts, reflecting higher refining costs and stronger demand from commercial vehicles. However, diesel engines generally extract more miles from each gallon, which can offset the higher purchase price depending on your mileage.

Factors Influencing Diesel Prices

Several factors contribute to the fluctuating prices of diesel fuel. One of the primary influencers is the global crude oil market. Any changes in crude oil prices, influenced by geopolitical events or supply and demand dynamics, can have a significant impact on the cost of diesel at the pump. Additionally, government taxes and levies, such as fuel duty and VAT, also play a role in determining the final price consumers pay for diesel.

What Makes Up the Diesel Price at the Pump?

The price of diesel at UK forecourts breaks down into:

  • Crude oil — the base cost, fluctuating with global commodity markets
  • Refining — diesel requires more refining steps than petrol, contributing to its slightly higher pump price
  • Fuel duty — the same as petrol (currently 52.95p per litre), a fixed government tax
  • VAT — charged at 20% on top of the duty-inclusive price
  • Retailer margin — typically a few pence per litre

As with petrol, taxation makes up a substantial portion of what you pay — over half the pump price goes directly to the government via fuel duty and VAT.

Is Diesel Still Worth It?

Despite being more expensive per litre, diesel remains a strong choice for high-mileage drivers. Diesel engines typically achieve 15–20% better fuel economy than equivalent petrol engines, meaning you travel further on each gallon. On a long motorway commute, a 50 MPG diesel will cover noticeably more miles per tank than a 40 MPG petrol car.

However, for drivers covering mainly short urban journeys, the fuel economy advantage diminishes — diesel engines need to warm up fully to operate efficiently, and frequent short trips can also increase maintenance costs. For a full comparison, see our guide on petrol vs diesel running costs.

Diesel Prices and Your MPG

To find out exactly what you're paying per mile for diesel, you need your car's real-world MPG figure. Divide the gallon price by your MPG to get a cost-per-mile figure. For example, at £6.59 per gallon with a car doing 50 MPG, you're spending around 13.2p per mile on fuel.

Use our free MPG calculator to calculate your actual fuel cost per mile based on your real driving data. You can also track how pump prices have changed over the past year on our UK fuel prices page.

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