Factor of Safety Calculator
FoS against yield and ultimate, with typical industry target bands.
Typical targets: buildings 1.5โ1.67 (yield), pressure vessels 3.5โ4 (ultimate), lifting gear 4โ6, elevator ropes 10+. The factor covers what you DON'T know โ loads, flaws, math.
Formula
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates โ verify with a qualified professional before making decisions. Read the full disclaimer.
Factor of Safety Calculator is a free factor of safety for design engineers, metallurgists and QA inspectors โ instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Factor of Safety Calculator
FoS against yield and ultimate, with typical industry target bands. The calculation implements n_y = ฯ_y/ฯ_work; n_u = ฯ_u/ฯ_work (Shigley; ASME/IS code factors). Typical targets: buildings 1.5โ1.67 (yield), pressure vessels 3.5โ4 (ultimate), lifting gear 4โ6, elevator ropes 10+. The factor covers what you DON'T know โ loads, flaws, math.
How to use Factor of Safety Calculator
- 1Enter Yield strength in MPa.
- 2Enter Ultimate strength in MPa.
- 3Enter Working stress in MPa.
- 4Read FoS on yield, FoS on ultimate instantly โ no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Factor of Safety Calculator?
- โImplements the standard formula โ n_y = ฯ_y/ฯ_work; n_u = ฯ_u/ฯ_work
- โReference cited on-page: Shigley; ASME/IS code factors
- โOne-click SI โ Imperial toggle โ values convert in place, physics stays in SI
- โBuilt-in engineering verdict flags out-of-range results instantly
- โRuns entirely in your browser โ nothing uploaded, free forever
Frequently asked questions
What formula does the Factor of Safety Calculator use?+
It computes n_y = ฯ_y/ฯ_work; n_u = ฯ_u/ฯ_work, per Shigley; ASME/IS code factors. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Typical targets: buildings 1.5โ1.67 (yield), pressure vessels 3.5โ4 (ultimate), lifting gear 4โ6, elevator ropes 10+. The factor covers what you DON'T know โ loads, flaws, math.
Where do the material property defaults come from?+
Defaults are standard handbook values (ASM, manufacturer datasheets, the cited standard). Always substitute certified values from your material's test certificate for critical work.
Is the Factor of Safety Calculator free to use?+
Yes โ completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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