Calculator
Example data table
| Scenario | Initial tread | Current tread | Distance | Surface | Alignment | Adjusted wear rate | Remaining distance |
|---|---|---|---|---|---|---|---|
| Haul truck, mixed roads | 16.0 mm | 10.0 mm | 12,000 km | Mixed | Fair | 0.90 mm / 1000 km | ~9,300 km |
| Loader, rough jobsite | 20.0 mm | 14.0 mm | 6,000 km | Jobsite | Poor | 2.10 mm / 1000 km | ~5,900 km |
| Trailer, paved routes | 14.0 mm | 11.5 mm | 18,000 km | Paved | Good | 0.14 mm / 1000 km | ~70,000 km |
Formula used
First, the measured tread loss is: Δt = tinitial − tcurrent.
The base wear rate per 1000 distance units is: Rbase = (Δt / D) × 1000.
Condition-adjusted wear rate applies multipliers: Radj = Rbase × Mposition × Msurface × Malignment × Mload × Mpressure × Mduty × Mtemp.
Remaining distance to a limit tread tlimit is: Dremain = ((tcurrent − tlimit) / Radj) × 1000.
How to use this calculator
- Measure tread depth at three points and average them.
- Enter the baseline tread and the latest tread measurement.
- Enter distance driven since the baseline inspection.
- Choose realistic jobsite conditions: surface, alignment, load, and pressure.
- Click Calculate to view the results above the form.
- Use Download CSV for records, and PDF for a report.
Professional guide
1) Why tire wear matters on projects
Construction fleets lose productivity when tires fail unexpectedly. Faster wear increases fuel use, braking distance, and vibration on compactors, loaders, and haul trucks. A tread plan reduces downtime and keeps equipment available during critical pours, lifts, and haul windows.
2) Measure tread the same way every time
Record tread at three points across the width and average the readings. Use the same gauge, the same locations, and similar temperature conditions. Note irregular patterns: center wear often links to over-pressure, shoulder wear to under-pressure, and feathering to toe misalignment.
3) Convert observations into a wear rate
The calculator first computes tread consumed, then normalizes it by distance to produce a base wear rate per 1000 distance units. This creates a comparable metric across machines, routes, and tire sizes, even when inspections occur at different intervals.
4) Understand condition multipliers
Jobsite surfaces, alignment quality, load level, pressure deviation, duty cycle, and heat each influence wear beyond pure mileage. Multipliers model that impact so a tire used on rough haul roads is not forecasted using a paved-road rate. Use conservative inputs for safety.
5) Forecast remaining distance to a limit
Remaining tread equals current depth minus the chosen limit depth. Dividing remaining tread by the adjusted wear rate yields projected remaining kilometers or miles. Pair this with average daily distance to estimate days left and schedule replacement before a weekend or shift change.
6) Rotation and alignment reduce uneven wear
Rotations redistribute scrub between axles and positions. On mixed-site fleets, many managers rotate every 6,000 to 10,000 km, then shorten the interval if steer tires show rapid edge wear. Alignment checks after curb strikes, potholes, or suspension repairs prevent costly scalloping.
7) Control pressure, load, and temperature
Small pressure errors compound into heat. Under-inflation flexes sidewalls, raising temperature and accelerating tread loss; overload adds similar stress. Track average load as a percent of rated capacity and verify pressures when tires are cold. Reduce harsh braking on descents to limit thermal spikes.
8) Use exports for audits and costing
Save CSV outputs with unit, date, and asset ID to build a maintenance history. Over time, compare wear rates by route, operator, surface, and season. This supports budgeting, warranty discussions, and replacement timing, and helps prioritize alignment work with the highest return. Include tire cost per hour and capture failures to quantify true lifecycle performance consistently.
FAQs
1) What legal limit should I use?
Use your jurisdiction and fleet policy. Many road tires use 1.6 mm, while off-road or safety-critical work may replace earlier. Set the limit that matches compliance rules and traction needs.
2) Can I enter miles and inches?
Yes. Choose miles for distance and inches or 32nds for tread. The calculator converts internally to keep formulas consistent, then shows results in your selected units.
3) Why is “current tread” higher than “initial” rejected?
If current exceeds initial, the baseline was recorded incorrectly, the gauge method changed, or the tire was rotated or replaced. Recheck the measurements and ensure distance reflects the same tire and inspection period.
4) How should I interpret the risk level?
Risk summarizes how strongly your conditions tend to accelerate wear. High risk suggests immediate checks for alignment, pressure, load, and heat drivers. It is a prioritization flag, not a safety certification.
5) How often should I measure tread on-site?
For mixed surfaces, measure weekly or every 1,000–2,000 km, whichever comes first. Increase frequency if you see uneven wear, frequent curb strikes, or high operating temperatures.
6) Do multipliers replace inspections?
No. Multipliers help forecasting, but physical inspections find cuts, punctures, sidewall damage, and abnormal patterns. Use the calculator to schedule work, then verify with real measurements.
7) The PDF button does nothing. What can I check?
PDF export needs a calculated result on the page and an internet connection for the library. Disable strict script blockers for the page, then recalculate and try again.