Tire Life and Cost Per Mile Calculator

How it works

A set of tires is paid for once and used up over its tread life, so its cost per mile is the installed price divided by the miles the set is expected to last. Multiplying by the miles you drive in a year gives the yearly cost, and dividing the expected life by miles per year gives how many years the set lasts.

The expected life can be entered directly, for example from the manufacturer's treadwear warranty, or estimated from the Uniform Tire Quality Grading (UTQG) treadwear grade on the sidewall. The estimate multiplies the grade by a miles-per-point figure that you can change. That figure is a rough rule of thumb, not part of the standard: federal rules describe the grade only as a comparison between tires.

Under 49 CFR 575.104, "a tire graded 150 would wear one and one-half (1 1/2) times as well on the government course as a tire graded 100." So whatever miles-per-point figure you use, a higher grade scales the estimate in proportion, and the comparison between two tires is more meaningful than either absolute number.

The replacement date is the installation date plus the years of life, counted in days at your average daily distance and rounded down to a whole day.

Formula

expected life (UTQG) = treadwear grade × miles per point
cost per mile        = set price ÷ expected life
cost per year        = cost per mile × miles per year
years of life        = expected life ÷ miles per year
replacement date     = installation date + ⌊expected life × 365 ÷ miles per year⌋ days

Example

A set costing $800 installed and expected to last 60,000 miles costs 800 ÷ 60,000 = $0.0133, or 1.33¢, per mile. At 15,000 miles a year that is $200 a year, and the set lasts 60,000 ÷ 15,000 = 4 years: installed October 1, 2026, it reaches its expected life around September 30, 2030 (1,460 days, with February 29, 2028 in between).

Estimated from UTQG grades at 100 miles per point, an $800 set graded 300 is put at 30,000 miles (2.67¢ per mile, $400 a year), and one graded 450 at 45,000 miles (1.78¢ per mile, about $266.67 a year): the 450 tire lasts 1.5 times as long, as the federal grading text describes.

Assumptions and limitations

• Tread life is an estimate. Actual wear depends on driving habits, alignment, inflation pressure, rotation, road surfaces and climate; the UTQG text itself says relative performance "may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate."
• UTQG treadwear grades are assigned by the tire manufacturer from a government test course and are meant for comparing tires. The miles-per-point figure is a rule of thumb you enter, not an official conversion. Winter tires and some other types are not graded.
• The whole set is assumed to wear out together and be replaced at once. Replacing tires early, for damage or age, raises the cost per mile.
• Prices are figures you enter; the default is illustrative. Effects of tires on fuel economy are not counted.
• This is an estimate, not a substitute for the tire or vehicle manufacturer's guidance or an inspection of the tires.

Frequently asked questions