Driving Cost Calculator
Calculate the full cost of a drive: fuel, per-mile running costs, tolls and parking, split per person, in mpg or L/100 km, with the 2026 IRS rate.
Work out what a drive really costs: fuel, plus any per-mile running costs, tolls and parking, with the total split between everyone in the car. It works in US units (miles, mpg, dollars per gallon) or metric (km, L/100 km, price per litre). In US mode it also shows the trip's value at the 2026 IRS business mileage rate, as a dated comparison benchmark.
How to use this tool
- Choose US or metric units.
- Enter the one-way distance and tick round trip if you are driving back.
- Enter your car's fuel economy and the current fuel price.
- Optionally add running costs per mile, tolls, parking and the number of people sharing.
- Read the total, the cost per person and how much fuel you will use.
Formula
Fuel = distance ÷ mpg (or distance × L/100 km ÷ 100); total = fuel × price + distance × running cost + tolls + parking
Cost per person divides the total evenly. The IRS figure multiplies the miles by 76¢, the business rate for driving on or after July 1, 2026 (72.5¢ applied from January 1 to June 30).
Example
A 300-mile drive in a car that gets 30 mpg uses 300 ÷ 30 = 10 gallons. At $3.50 a gallon that is $35.00 of fuel. Add $10 of tolls and $15 of parking and the trip costs $60.00, or $20.00 each for three people.
Frequently asked questions
What is the difference between fuel cost and driving cost?
Fuel is only part of what a car costs to run. Tyres, oil changes, repairs and depreciation also grow with every mile. Enter an estimate per mile to include them, or compare with the IRS rate, which is an all-in benchmark.
How do I convert mpg to L/100 km?
Divide 235.21 by the US mpg figure. For example, 30 mpg is about 7.84 L/100 km. For UK (imperial) mpg, divide 282.48 by the mpg instead.
What is the 2026 IRS mileage rate?
For business driving it is 72.5 cents per mile from January 1 to June 30, 2026, and 76 cents per mile from July 1, 2026 (Announcement 2026-11). The medical and moving rate rose from 20.5 to 23.5 cents at the same time.
How should we split gas money on a road trip?
Splitting the total evenly is simplest. Enter tolls and parking for the whole trip; the round-trip box doubles distance only. For passengers who join partway, calculate each leg separately.
Sources
Last updated: 2026