Tire Degradation Calculator

Both outputs come from the same square-root relationship — stint length ≈ √(2 × pit delta ÷ degradation per lap) — built around a 25-second pit-stop time penalty baked into the calculation. If your track's actual pit lane costs more or less than 25 seconds, both numbers will shift accordingly, so treat them as directional guidance rather than a precise answer for your specific pit lane.

The compound multiplier scales your entered base degradation rate directly — hard tires apply 0.7x that rate, medium applies 1.0x, and soft applies 1.5x — so a soft tire degrading at the same base rate as a hard tire will show more than double the wear over an equal stint. This changes every downstream output: average lap time, last-lap time, total time lost, and the optimal stint length all shift with the compound you select.

A linear model — a fixed number of seconds lost per lap — is simple to reason about and works reasonably well as a first-order approximation for moderate stint lengths, but real tires often hold pace initially and then degrade much faster near the end of their life. For longer stints or compounds known to 'fall off a cliff,' expect the calculator's predictions to be optimistic toward the end of the stint compared to reality.

Optimal Stint Length is the stint length that minimizes total race time for that degradation rate, while Crossover Lap is the specific lap number at which the cumulative time lost to tire wear exceeds the assumed pit-stop time cost. They're calculated from the same square root formula and will normally land close to the same number, but Crossover Lap is framed as 'the point of no return' within a stint already underway.