Cost Per Mile Calculator

How to Calculate Cost Per Mile

The cost per mile formula is straightforward:

Cost per mile = Total cost / Total miles

For example, if you spent $45 on fuel and tolls for a 150-mile trip, your cost per mile is $45 / 150 = $0.30 per mile. To convert this to cost per kilometre, divide by 1.60934 (the number of kilometres in a mile): $0.30 / 1.60934 = $0.186 per km.

What to Include in Your Total Cost

The right costs to include depend on your purpose:

Cost Per Mile vs Cost Per Km

Miles are used in the United States, United Kingdom, and a few other countries. Most of the world uses kilometres. The conversion is:

• 1 mile = 1.60934 kilometres
• Cost per km = Cost per mile / 1.60934
• Cost per mile = Cost per km x 1.60934

For example, $0.50 per mile equals $0.50 / 1.60934 = $0.311 per km. If you are a New Zealand driver and need to convert a mileage rate to kilometres, this calculator handles that automatically.

Standard Mileage Rates

Many employers and tax authorities publish standard mileage rates to simplify reimbursement. These rates are designed to cover the average cost per mile including fuel, wear and tear, and other expenses. In New Zealand, Inland Revenue (IRD) publishes kilometre rates for business use of private vehicles. In the United States, the IRS publishes a cents-per-mile rate annually. Always check the current rate for your jurisdiction, as these rates change each year.

Worked Example (Matches Default Output)

With the default values:

• Total cost: $45.00
• Distance: 150 miles

Cost per mile = $45.00 / 150 = $0.30 per mile

Distance in km = 150 x 1.60934 = 241.40 km

Cost per km = $45.00 / 241.40 = $0.186 per km

Cost per 100 miles = $0.30 x 100 = $30.00

Related Calculators

• Essential Calculators hub
• Fuel Cost Calculator: calculate the total fuel cost of a trip.
• Cost Per km Calculator: the metric equivalent using kilometres.
• km to Miles Converter: convert distances between kilometres and miles.
• Vehicle Loan Repayment Calculator: work out your car loan repayments.

Sources and method: Cost per mile formula: total cost divided by total miles travelled. Mile-to-kilometre conversion factor: 1 mile = 1.60934 km (exact international definition). IRD kilometre rates: ird.govt.nz/topics/income-tax/business-income-tax/kilometre-rates.

This calculator provides indicative estimates only. Actual costs vary depending on vehicle type, fuel prices, driving conditions, and included cost categories. For tax reimbursement purposes, check current IRD kilometre rates or the applicable rate for your country.