Bearing Life Calculator (ISO 281)

Predict rolling element bearing L₁₀ life using ISO 281 dynamic load rating methodology. Includes reliability and lubrication factors.

Bearings

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Formula

L₁₀ = (C / P)ᵖ × 10⁶ revolutions

p = 3 (ball) or 10/3 (roller). ISO 281 basic rating life.

ISO 281ISO 76 (static)

Assumptions & limits

  • •Equivalent load P must include radial and axial contributions
  • •Lubrication and contamination factors affect real life
  • •Catalog C and C₀ values required from manufacturer data
Bearing life guide

Worked example — ISO 281 life

  • →Dynamic capacity C from catalog (kN)
  • →Equivalent dynamic load P (kN)
  • →Ball bearing → exponent p = 3

L₁₀ (10⁶ rev) = (C/P)³. Convert to hours with L₁₀h = L₁₀ × 10⁶ / (60 × n) where n is rpm.

If axial load is present, form P = X·Fr + Y·Fa with catalog X, Y factors before using the formula.

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AluCalc 2026-07-12