Factor of Safety Calculator

Find the factor of safety from strength and working stress.

Factor of safety 2.5

Formula: FoS = strength ÷ working stress

Step-by-step with your numbers:

1. Values used:

2. Material strength = 250 MPa

3. Working stress = 100 MPa

5. Factor of safety = Material strength / Working stress = 250 / 100 = 2.5

Did we solve your problem today?

The factor of safety shows how much stronger a part is than it needs to be.

The math behind it

FoS = material strength ÷ actual working stress. Values above 1 mean a margin against failure.

250 MPa strength at 100 MPa working → FoS 2.5.

What's a typical value?

Often 1.5–4 depending on the application and consequences of failure.