A technical resource by Fault Ledger — Dual-Mode Bearing Sensors — Predictive Maintenance + Forensic Evidence

Bearing Life Calculator: L10 & L10a per ISO 281

Calculate basic L10 and adjusted L10a bearing service life per ISO 281. Determine expected operating hours from the bearing catalog dynamic load rating and your actual operating conditions.

Parameters

1.0=normal

Results

Click Calculate.

Understanding L10 Life

L10 is the number of revolutions (or hours at constant speed) that 90% of a group of identical bearings will reach or exceed before fatigue damage appears. It is a statistical prediction, not a guarantee for any individual bearing.

The Life Exponent

Ball bearings use an exponent of 3 (cubic relationship between load and life). Roller bearings use 10/3 (≈3.33) because line contact distributes load differently than point contact. This means roller bearings are slightly more sensitive to overloading.

Why Condition Monitoring Matters

Calculated bearing life assumes ideal conditions. Real-world factors like misalignment, contamination, and lubrication degradation can dramatically shorten actual life. Continuous vibration monitoring detects developing defects regardless of what the L10 calculation predicts.

IoT Bearings — Technical Resources for Bearing Condition Monitoring