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Fatigue Life Calculator

Goodman/Soderberg fatigue safety factor from mean and alternating stress.

Evaluate whether a component under fluctuating (mean + alternating) stress will achieve infinite fatigue life using the modified Goodman relation.

Reference: Modified Goodman Diagram

Fatigue Life Calculator (Goodman Criterion)

Inputs

Results

Endurance Limit (Se)
180.0MPa
Corrected Alternating Stress
60.0MPa
Goodman Equation Value
0.533(≤1 = safe)
Achieved Factor of Safety
1.88
⚠️ Does not meet target FOS — redesign needed

Formula Used

σa/Se + σm/Sut = 1/FOS
Endurance limit (Se) shown uses simplified database values — for precise design, apply full Marin correction factors (surface finish, size, load, temperature, reliability) to the base endurance limit.

⚠ For preliminary design and educational use only. Verify all results against applicable codes and standards before use in production or safety-critical applications.

About this calculator

Part of our Mechanical Calculators collection. Beams, bolts, springs, gears, bearings, and core ME calculations.

How it works

Evaluates fatigue life using modified Goodman and Soderberg criteria from mean and alternating stress, material endurance limit, yield strength, and UTS.

Enter your values in the inputs above and click CALCULATE. Results appear on the right without a page reload. No login and no server upload.

Privacy and accuracy

Every calculation runs locally in your browser. Your design data never leaves your device. Results are intended for preliminary engineering work. Always verify critical designs with qualified review and applicable standards before production use.

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