L10 basic rating life
10⁶ rev
Mechanics · Bearings
Bearing L10 Life Calculator
Estimate L10 basic rating life at 90% statistical reliability without treating it as guaranteed service life.
Created v1.0
By Thibaut Grzelak, Mechanical Analysis Engineer
03
MetricResults
Rating life in revolutions
rev
Basic rating life in hours
h
View calculation detailsFormulas, SI conversion, numerical substitution and resultsOpen ↓
Calculation note
Full calculation details
L10 is the basic rating life at 90% reliability for a sufficiently large group of identical bearings. C and P use the same force unit and n is constant. p = 3 for ball bearings and p = 10/3 for roller bearings. Modified rating life, variable spectra, lubrication, contamination and mounting conditions are excluded.
01Formulas and symbols
Formulas used
L10
(C / P)ᵖBasic rating life in million revolutionsp
p = 3 ; p = 10/3Exponent for the bearing typeL10h
10⁶ L10 / (60n)Basic rating life in hours02Assumptions and limits
Scope of validity
- L10 is the basic rating life at 90% reliability for a sufficiently large group of identical bearings.
- C and P use the same force unit and n is constant.
- p = 3 for ball bearings and p = 10/3 for roller bearings.
- Modified rating life, variable spectra, lubrication, contamination and mounting conditions are excluded.
03Validation example
Reference numerical case
- C = 30 kN, P = 10 kN, ball bearing and n = 1,500 rpm.
- L10 = 27 million revolutions.
- L10h = 300 h.
04Frequently asked questions
Questions about the calculation
What does L10 mean?
For a sufficiently large group of identical bearings under identical conditions, 90% are statistically associated with reaching or exceeding this rating life.
Is L10 guaranteed service life?
No. Actual life also depends on lubrication, contamination, installation, misalignment, wear, corrosion, electrical erosion and other conditions.
Why is L10h N/A at zero speed?
The hour conversion requires a non-zero rotational speed. Revolution life remains defined when P is positive.
05References
Technical references
- ISO 281:2007, Rolling bearings — Dynamic load ratings and rating life.
- ISO/TR 1281-1:2021, explanatory notes on ISO 281.