Fuel cost calculator
Enter how far you drive, what your vehicle returns and what you pay for fuel. The calculator does the arithmetic and nothing else — it holds no cost data about any vehicle and makes no assumption you cannot see and change.
Estimate your fuel cost
Your mileage, your vehicle's economy, the price you actually pay.
The values above are starting points so the form is not empty. They are not researched averages and they are not specific to any vehicle — edit every one of them.
How the numbers are worked out
Four lines of arithmetic, shown so you can check them
Petrol or diesel
- Gallons a year
miles a year ÷ combined MPG - Fuel cost a year
gallons a year × price per gallon - Cost a month
cost a year ÷ 12 - Cost per mile
cost a year ÷ miles a year
Electric
- kWh a year
(miles a year ÷ 100) × kWh per 100 miles - Charging cost a year
kWh a year × price per kWh
If a figure a calculation needs is missing or zero, the result shows an em dash rather than a number. We would rather show you nothing than a confident answer built on a division by zero.
About the values it starts with
Starting points, not research
The mileage, economy and price the form loads with are placeholders chosen so that the page shows a worked example instead of a row of dashes. They are not national averages, they are not sourced from anywhere, and they describe no particular vehicle. Replace all of them.
Fuel prices move week to week and vary by region and grade. Electricity is priced differently again — home charging on an overnight tariff and a public rapid charger are rarely anywhere near the same rate. The only price worth using here is the one you actually pay.
What this will not tell you
The honest boundaries of a fuel calculator
- It is not a prediction of what you will spend. Real fuel economy depends on how and where you drive, the weather, tyre pressure, load, and whether the vehicle is maintained. A single combined figure cannot carry all of that.
- It says nothing about a vehicle’s condition or safety. Fuel economy and reported safety issues are unrelated measures. For recalls, owner-reported complaints and NHTSA investigations, look the vehicle up on its own page.
- It only counts energy. Insurance, servicing, tyres, repairs, finance, registration and depreciation are all outside this calculation.
Finding the numbers to put in
Where each input actually comes from
- Miles a year
- Two odometer readings twelve months apart is the most reliable source. Insurance renewal paperwork and service records often carry a reading you can work from.
- Combined MPG
- The EPA publishes city, highway and combined estimates for most vehicles sold in the United States, and we show the ones we hold on each model-year page. Your own measured figure — from the MPG calculator — is better still, because it already reflects how you drive.
- Price per gallon or per kWh
- Your last receipt for fuel; your utility bill for electricity. Use the rate you pay, including any delivery charge, rather than a headline rate.