Calculating your tread life remaining is straightforward once you know the Tyre Life Remaining formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Tyre Life Remaining Calculator.
What is Tyre Life Remaining?
The Tyre Life Remaining calculation tells you your tread life remaining from a few simple inputs. The figure you are solving for here is the tread life remaining, expressed in percent.
The Tyre Life Remaining formula
This calculation combines several inputs through a multi-step method rather than a single one-line formula. Enter the values below and the calculator resolves each step in order. The inputs it needs are:
- Current tread depth — a value measured in mm. Example: 4 mm.
- New tread depth — a value measured in mm. Example: 8 mm.
- Legal minimum tread — a value measured in mm. Example: 1.6 mm.
How to calculate it step by step
- Write down the current tread depth (for example, 4 mm).
- Write down the new tread depth (for example, 8 mm).
- Write down the legal minimum tread (for example, 1.6 mm).
- Apply the formula above to get your tread life remaining.
- Double-check the result with the Tyre Life Remaining Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Current tread depth | 4 mm |
| New tread depth | 8 mm |
| Legal minimum tread | 1.6 mm |
| Tread life remaining | 37.50% |
With current tread depth of 4 mm, new tread depth of 8 mm and legal minimum tread of 1.6 mm, the tread life remaining works out to 37.50%.
Example 2
With current tread depth of 8 mm, new tread depth of 8 mm and legal minimum tread of 1.6 mm, the tread life remaining works out to 100.00%.
| Result | Value |
|---|---|
| Tread life remaining | 100.00% |
Example 3
With current tread depth of 2 mm, new tread depth of 8 mm and legal minimum tread of 1.6 mm, the tread life remaining works out to 6.25%.
| Result | Value |
|---|---|
| Tread life remaining | 6.25% |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Tyre Life Remaining Calculator does it instantly, for free, with the formula and a worked example built in.
Related calculators
Continue exploring automotive calculators with these tools: Engine Displacement Calculator, Compression Ratio Calculator, Horsepower to Torque Calculator, Gear Ratio Calculator, Tire Size Calculator.