Shear Stress Calculator
Calculate average shear stress in a material from an applied shear force and cross-sectional area.
How this calculator works
Shear stress builds up when a force tries to slide one layer of material past another, rather than pulling or pushing straight through it. This calculator takes the shear force applied to a part and the cross-sectional area resisting that force, then divides one by the other to get the average shear stress.
Formula: Shear stress = Shear force ÷ Cross-sectional area (τ = V/A).
Worked example
A 3,000 lb shear force on a 14 in² cross-section:
- Shear force: 3,000 lb
- Cross-sectional area: 14 in²
- Shear stress: 3,000 ÷ 14 ≈ 214.29 psi
Notes
This gives the average shear stress across a cross-section. Actual shear stress distribution in a beam varies through the depth, highest at the neutral axis and zero at the outer fibers, following the VQ/Ib formula, so this average figure is a simplified check. It is most useful for bolt and pin connections, where shear is fairly uniform across the fastener.
For beam web shear checks specifically, engineers typically use the more detailed VQ/Ib distribution rather than this average.
How to use
Enter the shear force applied and the cross-sectional area resisting it, in consistent units. The calculator returns the average shear stress in psi, which works well as a quick check for bolted or pinned connections, but should be paired with a more detailed method for beam web shear.
This is a planning estimate using standard mechanics-of-materials formulas, not a substitute for engineering design. Confirm actual stress limits and material allowables with a licensed structural or mechanical engineer.
Frequently asked questions
What is shear stress?
Shear stress is the stress caused by a force trying to slide one part of a material past another, rather than stretching or compressing it straight through. A pair of scissors cutting paper, or a bolt resisting a sideways load, are both examples of shear. This calculator finds the average shear stress across the cross-section carrying that force.
How is shear stress different from axial stress?
Axial stress comes from a force acting straight through a cross-section, pulling or pushing the material along its length. Shear stress comes from a force acting parallel to the cross-section, trying to slide layers of material sideways past each other. They use the same basic formula, force divided by area, but describe different ways a material can fail.
Is this calculator accurate for beam web shear checks?
This calculator gives the average shear stress, which is a simplified check. Actual shear stress in a beam varies through its depth, peaking at the neutral axis and dropping to zero at the outer edges, following the more detailed VQ/Ib formula. For beam web shear specifically, engineers typically use that distribution rather than the average figure.
When is the average shear stress formula good enough?
The average shear stress formula works well for connections like bolts and pins, where the shear force is reasonably uniform across the fastener's cross-section. It is a quick, useful check for that kind of connection, but it is a simplification for beam webs and other cases where shear stress varies significantly through the material.
Estimates only. Verify quantities with your supplier before purchasing.