basic

S-N Curve Fatigue Life Cycle Calculator

N = (S_u/2S)^(1/b) × N_ref — cycles to failure estimate.

Estimates fatigue life (cycles to failure) from applied stress amplitude and S-N curve parameters (ultimate strength and fatigue exponent).

Priya Venkatesan By Priya Venkatesan
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

N = (C / S_a)^(1/b); C ≈ 0.9 × S_u

In depth

Estimates fatigue life (cycles to failure) from applied stress amplitude and S-N curve parameters (ultimate strength and fatigue exponent).