Journey Fuel Cost Calculator
This fuel cost calculator for UK drivers works out what a journey costs in petrol, diesel or electricity, per trip, per week and per year. It uses this week’s average UK pump prices and the current price cap rate for home charging, so the answer reflects what drivers pay today.
Worked example: a 15-mile commute in a petrol family car
A 30-mile trip at 42 mpg uses 3.25 litres of petrol at 175.28p a litre, which works out at 19.0p a mile. 5 trips a week for 52 weeks a year.
| Fuel | Economy | Price | Per trip | Per year |
|---|---|---|---|---|
| Petrol your choice | 42 mpg | 175.28p | £5.69 | £1,480 |
| Diesel | 52 mpg | 200.04p | £5.25 | £1,364 |
| Electric, charged at home cheapest | 3.5 miles/kWh | 26.32p | £2.26 | £587 |
| Electric, public rapid charger | 3.5 miles/kWh | 79.00p | £6.77 | £1,761 |
Rows you did not choose use the family car example economy figures and this week’s published prices.
Estimates for general information only, not advice. See Important information below.
Written by Anthropic’s Claude AI from the figures above. What you enter is sent to it to write the explanation, so please don’t include personal details.
Cost per 100 miles at this week’s prices
What 100 miles costs in fuel at different fuel economy figures, using the same prices as the calculator.
| Fuel economy | Petrol at 175.28p | Diesel at 200.04p |
|---|---|---|
| 25 mpg | £31.87 | £36.38 |
| 30 mpg | £26.56 | £30.31 |
| 35 mpg | £22.77 | £25.98 |
| 40 mpg | £19.92 | £22.73 |
| 45 mpg | £17.71 | £20.21 |
| 50 mpg | £15.94 | £18.19 |
| 55 mpg | £14.49 | £16.53 |
| 60 mpg | £13.28 | £15.16 |
| 65 mpg | £12.26 | £13.99 |
| 70 mpg | £11.38 | £12.99 |
| Efficiency | Home at 26.32p | Rapid at 79p |
|---|---|---|
| 2.5 miles/kWh | £10.53 | £31.60 |
| 3.0 miles/kWh | £8.77 | £26.33 |
| 3.5 miles/kWh | £7.52 | £22.57 |
| 4.0 miles/kWh | £6.58 | £19.75 |
| 4.5 miles/kWh | £5.85 | £17.56 |
Prices used
- Petrol 175.28p and diesel 200.04p a litre: UK average pump prices for the week of 12 October 2026, from the Department for Energy Security and Net Zero, Weekly road fuel prices (published 13 October 2026).
- Home charging 26.32p per kWh: Great Britain average electricity unit rate under the energy price cap for 1 October to 31 December 2026, paying by Direct Debit, from Ofgem. The standing charge is left out because you pay it whether or not you charge.
- Public rapid charging 79p per kWh: average pay-as-you-go price at rapid and ultra-rapid chargers in September 2026, from the Zapmap Price Index (updated 7 October 2026).
- A UK gallon is 4.54609 litres. The vehicle-type figures are rounded examples to get you started, not measured averages.
How it works and where the numbers come from
The calculator divides your miles by your car's miles per gallon, converts the gallons to litres at 4.54609 litres to the UK gallon and multiplies by the price per litre. Petrol and diesel prices are the UK averages for the week of 12 October 2026 from the Department for Energy Security and Net Zero's Weekly road fuel prices: 175.28p a litre for petrol and 200.04p for diesel.
For an electric car it divides the miles by miles per kWh and multiplies by the unit price. Home charging uses Ofgem's price cap unit rate of 26.32p per kWh for 1 October to 31 December 2026. Public rapid charging uses 79p per kWh, the Zapmap Price Index average for September 2026. Type in your own price if yours is different. The vehicle presets are rounded examples, so use your own car's figure where you can.
Worked example
Take a 15-mile commute each way, five days a week, in a petrol family car doing 42 mpg. The 30-mile round trip uses 3.25 litres, which costs £5.69 at 175.28p a litre. That is £28.46 a week, or about £1,480 a year. An electric car doing 3.5 miles per kWh, charged at home, would cost £2.26 a trip, or about £587 a year. Using only public rapid chargers, it would cost £6.77 a trip.
Questions
Is this a car running cost calculator?
Only for fuel or charging. It leaves out insurance, tax, servicing and depreciation, so treat it as the fuel part of a running cost budget.
Why does the petrol cost calculator use UK gallons?
UK mpg figures are quoted in imperial gallons of 4.54609 litres. A US gallon is smaller, so check the figure you enter is a UK one.
How accurate is the EV charging cost calculator?
It is only as accurate as the efficiency figure you give it, and it does not add the energy lost while a car charges. If you are on an overnight or EV tariff, enter its rate instead.
How often do the prices change?
The government publishes pump prices every week and Ofgem resets the price cap every three months. Each price used here is dated in the calculator.
Does the electricity standing charge count?
No. You pay it whether or not you charge a car, so only the unit rate is used.
Important information
This tool gives general information and estimates only. It is not financial, tax, legal, medical or other professional advice, and it does not take your personal circumstances into account.
Fuel and electricity prices change every week, and real fuel economy depends on your vehicle, load, weather and driving. Treat the figures as an estimate.
The figures are based on the published sources and dates shown on this page. Prices, rates and rules change, so they may be out of date by the time you read this. Check them with the supplier, provider or official source, or ask a qualified professional, before you make a decision.
The AI-written explanation is produced automatically by Anthropic's Claude from the figures on this page. It can contain mistakes and should not be relied on.
We don't keep what you enter. If you use the AI explanation, what you entered is sent to Anthropic so it can write it.
You use this tool at your own risk. News Bug accepts no responsibility for any loss, cost or decision made as a result of using it, as far as the law allows.