Petrol vs diesel fuel cost calculator

With petrol, LPG and diesel prices having reached record highs, it pays to know exactly how much your current car costs to run. Our free fuel-cost calculator lets you quickly work out the annual fuel costs for your car and even compare it to another model.

To find out your fuel costs, you'll just need the following:

• The price per litre for petrol, LPG or diesel (whichever your car requires)
• The mpg (miles per gallon) figure for your car
• Your estimated total annual mileage (people who complete our annual car survey typically drive around 7,050 miles each year)

Of course, price isn't the only thing you should consider when buying a new car. Only cars that are reliable, economical, comfortable, safe and good to drive can become a Which? Best Buy. Head to our best cars to find out the models we recommend. 

• Current average fuel prices are available on sites such as the AA, but you can look up prices near you using services such as PetrolPrices.com.

Compare fuel costs for two cars

To enter details for a second car, click the Add another car for comparison button, then enter the relevant details.

If you're unsure of the mpg for the car you're thinking of buying, be sure to check out our new and used car reviews.

We ignore manufacturer claims and calculate accurate mpg figures for every car we test.

To obtain these figures, we simulate driving in various locations (city and out-of-town roads, plus motorways).

As well as providing you with an overall mpg figure, we report separate figures for each driving scenario. This lets you see what the numbers mean for your wallet based on the driving you're most likely to be doing.

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Cut your driving costs

Spending too much money on petrol, diesel or electricity for your car? By making simple adjustments to the way you drive, you can make your fuel go further.

We explain all in our guide on how to save fuel and other money-saving driving tips.