Bearing Life Calculator
Calculate L10 bearing fatigue life in revolutions and hours for ball and roller bearings.
How it works
- 1Enter the bearing’s dynamic load rating C and the equivalent dynamic load P in the same unit system.
- 2Select ball bearing (p = 3) or roller bearing (p = 10/3) and enter the operating speed in rpm.
- 3The calculator applies L10 = (C / P)^p to give life in million revolutions, hours, and years at continuous 24/7 operation.
Use cases
- Verifying that a selected bearing meets the required service life for a gearbox or conveyor drive.
- Comparing ball and roller bearing options under the same load conditions to choose the longer-lived design.
- Estimating maintenance intervals and replacement schedules based on operating speed and load.
Frequently asked questions
What is L10 bearing life?
L10 is the basic rating life — the number of million revolutions (or hours at a given speed) that 90% of a group of identical bearings will reach or exceed before fatigue failure. It is L10 = (C / P)^p.
What exponent p should I use?
Use p = 3 for ball bearings and p = 10/3 ≈ 3.333 for roller bearings (cylindrical, tapered, spherical). These values are defined in ISO 281.
Worked example: C = 30 kN, P = 3 kN, ball bearing.
L10 = (30 / 3)³ = 10³ = 1000 million revolutions. At 1500 rpm that is about 11,111 hours, or roughly 1.27 years of continuous operation.
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