Brake Pad Life Calculator
Estimate the remaining life of your brake pads from their measured wear so far — how many more miles before they hit the minimum thickness.
How it works
Wear rate = (new − current) ÷ miles · Miles left = (current − minimum) ÷ wear rate
Brake wear is close to linear with distance, so measuring how much friction material disappeared over a known mileage gives a reliable wear rate. Multiply the material still above the minimum by that rate — inverted — to project the miles remaining. The estimate assumes similar driving ahead: a lot of city stop-and-go or towing wears pads far faster than steady highway miles.
Worked example
Pads started at 12 mm and measure 7 mm after 20,000 miles, so 5 mm wore over that distance — 0.25 mm per 1,000 miles. With a 3 mm replace point, 7 − 3 = 4 mm remain, giving 4 ÷ 0.00025 ≈ 16,000 more miles.
Frequently asked questions
At what thickness should brake pads be replaced?
Most manufacturers call for replacement around 2–3 mm of friction material. Below that, braking performance drops and you risk scoring the rotor with the backing plate. Set the replace-at field to your car’s spec.
How do I measure pad thickness?
Look through the caliper or wheel spokes at the pad against the rotor, or remove the wheel and measure the friction material with a caliper or a brake pad gauge. Measure the most worn pad on the axle.
Why is my real pad life different from the estimate?
Wear rate depends heavily on driving style, load and whether it is front or rear pads. The projection is only as good as the assumption that future driving matches the past — treat it as a planning figure, not a guarantee.
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This calculator is for educational purposes. Double-check important results before acting on them.