PETROL JOURNEY COSTS
Petrol cost calculator
Work out how much petrol a journey will use and what it will cost using your mileage, MPG and the pump price.
CALCULATE YOUR JOURNEY
Petrol journey cost
PETROL COST FORMULA
How to work out petrol cost
The calculation starts by converting your car’s UK MPG into litres used for the journey. Miles ÷ MPG gives imperial gallons, then the result is multiplied by 4.54609 to convert gallons to litres. Litres are then multiplied by the petrol price in pounds per litre.
For the best estimate, use the MPG your car actually achieves rather than an official laboratory figure. Short urban trips, cold weather, heavy traffic and higher speeds can all increase petrol consumption.
How much petrol will I use?
The result panel shows litres as well as pounds. That makes the calculator useful when you want to know both how much a journey costs and roughly how much fuel needs to be in the tank.
Petrol cost per mile
Cost per mile makes different journeys and vehicles easier to compare. It is fuel-only: insurance, servicing, tyres, depreciation, parking and tolls are not included.
QUESTIONS ANSWERED
Frequently asked questions
How much does 100 miles cost in petrol?
It depends on your MPG and petrol price. The calculator shows a 100-mile figure automatically from the values you enter.
Should I use official or real-world MPG?
Real-world MPG is usually better for budgeting because it reflects your own car and driving conditions.
Does the calculator use UK gallons?
Yes. MPG calculations use the UK imperial gallon.
Can I calculate a return journey?
Yes. Tick “Include the return journey” and the distance is doubled before fuel cost is calculated.
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