Sources and scope for this page: Industry convention — no single governing standard (conventional usage, definitions vary between sources), covering the definition of l10 life. No independent source check is recorded for this page: the content rests on the sources listed and on the working shown on the page. How sources, methods and updates are recorded.
Definition
L10 is a statistical rating, not a minimum. One bearing in ten is expected to fail before reaching it, which is why critical applications use L5 or L1 and accept a shorter predicted life.
The calculation is L10 = (C ÷ P)p × 106 revolutions, with p = 3 for ball bearings and 10/3 for roller. Because the exponent is 3, halving the load multiplies the life by eight.
Common misuse
Treating L10 as a guaranteed minimum life. It is the 10th percentile, not the floor.