Mechanical & Civil Engineering
Stress Concentration Factor (Kt) Calculator
Estimate the theoretical stress concentration factor Kt for a notch or hole in a loaded member.
Your inputs
Change any value to update the result instantly.
Stress concentration factor Kt
2.506
Max local stress
250.65 MPa
Nominal stress
100 MPa
d/W ratio
0.2
What this calculator does
Stress Concentration Factor (Kt) Calculator: Applies the standard mechanics-of-materials relationship for this load case so a student can see how the stress, strain or deflection follows from the geometry and the load.
What your result means
The headline figure tells you how hard the material is being worked, or how much it moves, under the load you entered. Compare it with the allowable value for your material and required factor of safety.
Formula and working
σmax = Kt · σnom
- 1
Collect the inputs
Geometry type = 1; Nominal stress = 100 MPa; Diameter/width ratio (d/W) = 0.2
- 2
Apply the formula
σmax = Kt · σnom
- 3
Result
Stress concentration factor Kt = 2.506
Frequently asked questions
Symbols and assumptions
- geometry
- Geometry type
- nomStress
- Nominal stress (MPa)
- dW
- Diameter/width ratio (d/W)
- • The material is homogeneous, isotropic and loaded within its linear-elastic range.
- • Inputs are entered in a consistent unit system, as labelled on each field.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • This is an educational estimate for learning and checking, not a design deliverable.
- • Real design must follow the governing code or standard for your jurisdiction and be reviewed and signed off by a qualified engineer.
- • Safety factors, load combinations and material certification are the responsibility of the designer, not of this page.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
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