Bearing Life Calculator

ISO 281 L10 rating life — calculate operating hours for any deep groove ball bearing.

Inputs

Bearing model (optional — pre-fills C)

Dynamic load rating C (kN) — from bearing catalogue

Equivalent dynamic load P (kN) — applied bearing load

Rotational speed n (RPM)

Bearing type

Ball (p = 3) Roller (p = 10/3)

ISO 281 Formula

L10 = (C / P) ^ p

L10h = L10 × 10⁶ / (60 × n)

p = 3 (ball) or 10/3 (roller). L10 in millions of revolutions, L10h in hours.

Enter C, P, and RPM, then click Calculate.

Target L10h by Application

Electric motors (8h/day)20,000–40,000 h

Industrial pumps17,500+ h

Industrial gearboxes30,000 h

Agricultural machinery3,000–5,000 h

Conveyor systems30,000–100,000 h

Frequently Asked Questions

What is L10 bearing life?

L10 is the basic rating life per ISO 281: the number of revolutions (or hours) that 90% of a group of identical bearings will complete without fatigue failure under a given load. 10% may fail before reaching L10.

What is the ISO 281 formula?

L10 = (C/P)^p, where C is dynamic load rating (kN), P is equivalent dynamic load (kN), and p = 3 for ball bearings or 10/3 for roller bearings. L10h = L10 × 10^6 / (60 × n), where n is speed in RPM.

How do I find the dynamic load rating C?

C is listed in the bearing's datasheet. For common 6200 series, typical values: 6204=12.8kN, 6205=14.0kN, 6206=19.5kN. You can also select a model above to pre-fill C automatically.

What is equivalent dynamic load P?

P is the combined radial and axial load the bearing "sees," accounting for load direction. For pure radial load with no axial component, P = Fr (radial force). For combined loading: P = X·Fr + Y·Fa, where X and Y are factors from the bearing catalogue.

What is a realistic bearing life target?

Electric motors: 20,000–40,000 h. Industrial gearboxes: 30,000 h. Automotive: 3,000–5,000 h. Pumps: 17,500 h (ISO 10816 general guideline). If your calculated L10h is less than twice the target, consider a larger bearing.

Disclaimer: This tool provides ISO 281 basic rating life (L10) as a guide for initial bearing selection. Modified rating life (Lnmh) per ISO 281:2007/Amd.2:2012 depends on contamination, lubrication adequacy, and operating conditions not captured here. Always verify with manufacturer data for critical applications.