Tire Replacement Projection Calculator
Project when tires reach a replacement depth from recorded tread wear. Get remaining miles, kilometers and months to 2/32 or 4/32 inch.
Extrapolate recorded tread wear.
Tire Replacement Projection Calculator: Tire Size Inputs
Compare two tire sizes here. Use the formulas and reference tables below for this tool's specific calculation.
How Tire Replacement Projection Calculator Works?
The Tire Replacement Projection Calculator works by multiplying the usable tread left by the measured distance per unit of wear. The tool uses 4 steps.
Enter the current reading
Type the current tread, for example 7/32 in (5.6 mm).
Enter the wear rate
Type the measured rate, for example 4,000 mi per 1/32 in.
Pick the threshold
Choose 2/32 in or 4/32 in.
Enter annual distance
Type yearly driving, for example 12,000 mi (19,312 km). The calculator returns 12,000 mi and 12 months to 4/32 in.
Tire Replacement Projection Calculator Formula
The Tire Replacement Projection Calculator formula is Distance left = (n_now − n_min) × D₁, where D₁ is the distance per 1/32 in of wear.
D_left = (n_now − n_min) × D₁t = D_left ÷ D_year × 12 monthsD_left,km = D_left,mi × 1.609344- n_now, n_min
- Current and threshold tread (32nds)
- D₁
- Measured distance per 1/32 in
- D_year
- Annual distance
Worked example
A tire at 6/32 in wearing 5,000 mi per 1/32 in reaches 2/32 in in 20,000 mi (32,187 km) and 4/32 in in 10,000 mi. At 12,000 mi a year, replacement at 4/32 in falls 10 months out.
Tire Replacement Projection Calculator Conversion Table
The Tire Replacement Projection Calculator conversion table projects remaining distance and time for 6 tread and wear rate cases.
| Current tread | Wear rate | To 2/32 in | To 4/32 in | Months to 4/32 in at 12,000 mi/yr |
|---|---|---|---|---|
| 8/32 in | 3,000 mi per 1/32 | 18,000 mi (28,968 km) | 12,000 mi | 12 months |
| 7/32 in | 4,000 mi per 1/32 | 20,000 mi (32,187 km) | 12,000 mi | 12 months |
| 6/32 in | 5,000 mi per 1/32 | 20,000 mi (32,187 km) | 10,000 mi | 10 months |
| 5/32 in | 3,500 mi per 1/32 | 10,500 mi (16,898 km) | 3,500 mi | 4 months |
| 9/32 in | 2,500 mi per 1/32 | 17,500 mi (28,164 km) | 12,500 mi | 12 months |
| 4/32 in | 4,500 mi per 1/32 | 9,000 mi (14,484 km) | 0 mi | 0 months |
What is Tire Replacement Projection Calculator?
A Tire Replacement Projection Calculator is a tool that extrapolates recorded tread wear to forecast when tires reach a replacement depth. The projection turns tread readings into a date and a budget line.
The projection assumes the same roads, load and alignment as the period measured. A change in any factor changes the forecast.
Tire age caps the projection. Many tire and vehicle makers advise replacement at 6 to 10 years from manufacture regardless of tread.
What are the uses of Tire Replacement Projection Calculator?
There are 4 main uses of the Tire Replacement Projection Calculator, including budget planning and fleet scheduling.
Budget planning
Set aside money before replacement is due.
Fleet scheduling
Book tire replacements around vehicle downtime.
Season timing
Decide whether tires last through winter.
Trip planning
Check tires last through a long road trip.
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