🛡️ Factor of Safety Calculator
Calculate the factor of safety for a design by comparing material strength to the actual applied stress or load.
What factor of safety means
The factor of safety (FoS) compares a material’s or structure’s strength to the actual load or stress it experiences in service. A factor of safety greater than 1 means the design has margin before failure; the higher the number, the more conservative the design.
The formula
Factor of Safety = Material Strength / Working Stress, where material strength is typically the yield strength or ultimate tensile strength of the material, and working stress is the actual (applied) stress the part experiences under normal operating loads. Margin of safety is simply FoS − 1.
This is a general engineering reference calculation; required factors of safety vary widely by industry, application, and applicable design codes.