Stress & Strain Calculator

This calculator works out stress, strain and Young's modulus, the three quantities that describe how a material responds to being stretched or compressed. When a force is applied to a material, it deforms, and engineers describe this with two normalised measures rather than raw force and length. Stress is the force spread over the cross-sectional area, so it captures the intensity of the loading regardless of the part's size. Strain is the extension divided by the original length, the fractional stretch, a pure number. The ratio of stress to strain, while the material behaves elastically, is Young's modulus, a fundamental property of the material that measures its stiffness: a high modulus, like steel's, means it barely stretches under load, while a low modulus, like rubber's, means it stretches easily. These ideas underpin all of mechanical and structural engineering, from designing beams and cables to choosing materials. This tool computes them. You enter the applied force, the cross-sectional area, the original length, and the extension, and the calculator returns the stress, the strain, and Young's modulus, along with the force for reference. The results update as you type. Use it for materials science and engineering study, for analysing how a component will deform, or for finding a material's stiffness from a test. The relationships are stress equals force over area, strain equals extension over original length, and Young's modulus equals stress over strain. A useful sense of scale: Young's modulus is often very large, so it is usually quoted in gigapascals, with steel around 200, aluminium around 70 and rubber a tiny fraction of one. The calculation assumes the material is within its elastic limit, where stress and strain stay proportional and the deformation is reversible; beyond that point the simple relationship breaks down.

Stress = force / area. Strain = extension / length. Young's modulus = stress / strain. Assumes elastic behaviour. Steel ~200 GPa, aluminium ~70 GPa.