Fuel Cost Calculator
Estimate the fuel cost of any journey. Enter your distance, fuel efficiency, and fuel price to see how much your trip will cost.
Fuel Cost Calculator
Estimate the fuel cost of any journey
Miles per UK gallon. A typical car does 35-45 mpg.
Total Fuel Cost
£8.24
50 miles
5.7 L
1.3 UK gallons
£0.16
running cost
£0.16
per mile
£0.10
per km
How to Use This Calculator
Enter the distance of your journey in miles or kilometres. Toggle between units using the buttons below the distance input.
Set your vehicle's fuel efficiency in miles per gallon (mpg) or litres per 100 km. The unit automatically matches your chosen distance unit. UK mpg uses imperial gallons (4.546 litres), not US gallons.
Enter the current fuel price in pence per litre, pounds per litre, or pounds per gallon. The default is pence per litre, which matches how most UK forecourts display prices.
Enable the round trip toggle if you need to calculate the cost of a return journey. This simply doubles the distance for you.
Understanding Your Results
Total Fuel Cost shows the estimated cost of fuel for your journey in your selected currency. This is calculated from the distance, your vehicle's efficiency, and the fuel price you entered.
Fuel Needed shows the total volume of fuel required, displayed in both litres and UK gallons. Use this figure when planning whether you need to fill up before departing.
Cost per Mile/Kilometre shows your fuel running cost per unit of distance. This is useful for comparing driving costs against public transport or for calculating mileage reimbursement.
Frequently Asked Questions
How do I calculate the fuel cost of a journey?
Divide your journey distance by your vehicle's fuel efficiency (mpg) to get the number of gallons needed, then multiply by the price per gallon. Alternatively, convert your efficiency to litres per 100 km, multiply by the distance in km divided by 100, then multiply by the price per litre. This calculator handles all of that automatically.
What is a good mpg for a car in the UK?
A typical petrol car in the UK achieves between 35 and 50 mpg (UK gallons). Diesel cars tend to be slightly more efficient, often reaching 45 to 65 mpg. Hybrid vehicles can exceed 60 mpg, and the figure varies depending on driving conditions, vehicle age, and engine size.
What is the difference between UK gallons and US gallons?
A UK (imperial) gallon is approximately 4.546 litres, while a US gallon is approximately 3.785 litres. This means a UK gallon is about 20% larger than a US gallon. When comparing mpg figures, UK mpg will always appear higher than US mpg for the same vehicle because the gallon is larger.
How can I improve my fuel efficiency?
Maintain steady speeds and avoid harsh acceleration or braking. Keep your tyres inflated to the recommended pressure, as underinflated tyres increase rolling resistance. Remove unnecessary weight and roof boxes when not in use. Use the correct engine oil grade, and service your vehicle regularly. Driving at 60 mph rather than 70 mph on motorways can reduce fuel consumption by around 10%.
Should I use the advertised mpg figure for my car?
Official manufacturer mpg figures are measured under controlled laboratory conditions (WLTP cycle) and are useful for comparing vehicles. However, real-world fuel economy is typically 10-20% lower than the advertised figure due to factors like traffic, weather, driving style, and terrain. Use your actual mpg for more accurate cost estimates.
Is it cheaper to drive or take the train in the UK?
It depends on the journey. For solo travellers, trains can be cheaper on popular routes with advance tickets. However, for two or more passengers sharing a car, driving is often more economical, especially on longer journeys. Consider parking costs, tolls, and congestion charges when comparing. Use this calculator to find your driving cost and compare with rail fares.
Related Calculators
Found this calculator helpful?
Check out our other free calculators for everyday math problems.
View All Calculators