Bearing Life Calculator

Calculate L10 bearing life in revolutions and hours using the ISO 281 basic rating life equation for ball and roller bearings.

Dynamic Load Rating (C)

Equivalent Dynamic Load (P)

Operating Speed

RPM

Load-Life Exponent (p)

Tab to move between fields

L10 Life (Hours)

1,157 hrs

Adjusted L10 Life

1,157 hrs

L10 Life (Revolutions)125,000,000

L5 Life (95% Reliability)718 hrs

How to Use This Calculator

Enter the Dynamic Load Rating (C) in lb from the bearing manufacturer's catalog — this is the load at which 90% of bearings survive 1 million revolutions.
Enter the Equivalent Dynamic Load (P) in lb, combining radial and axial forces using P = XFr + YFa from the catalog X and Y factors.
Set the Operating Speed in RPM. Common motor-driven speeds are 1200, 1750, and 3600 RPM.
Select the Load-Life Exponent: p = 3 for ball bearings, p = 10/3 for roller bearings.
Review the L10 Life in hours — this is the service life at which 10% of bearings are expected to fail. The Adjusted L10 Life applies standard reliability and lubrication factors.
Compare the L5 Life (95% reliability) if higher confidence is required for critical machinery.

What each input means

Dynamic Load Rating (C): Basic dynamic load rating from the bearing catalog. The load at which 90% of bearings survive 1 million revolutions.
Equivalent Dynamic Load (P): Equivalent dynamic bearing load combining radial and axial forces. P = XFr + YFa (from bearing catalog).
Operating Speed: Rotational speed of the bearing. Must be within the bearing's speed rating.
Load-Life Exponent (p): Life exponent depends on bearing type. Ball bearings use p=3; roller bearings use p=10/3.

Identify Input Parameters
4 parameters
Dynamic Load Rating (C) = 10000, Equivalent Dynamic Load (P) = 2000, Operating Speed = 1800, Load-Life Exponent (p) = 3 = 4 input(s) provided
Calculate L10 Life
L10 Life
1157 = 1157
Calculate Adjusted L10 Life
Adjusted L10 Life
1157 = 1157
Calculate L10 Life
L10 Life
125000000 = 125000000
Calculate L5 Life
L5 Life
718 = 718

Engine last updated July 11, 2026. Checked against 1 independently-derived test — how we verify calculators.

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