Strain Calculator
Calculate strain from change in length.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Strain Calculator
Enter the original length and the change in length to calculate strain.
- Enter original length. The unstressed length of the material.
- Enter change. The elongation or compression.
- Read the result. Strain is dimensionless, shown as a ratio and percentage.
About the Strain Calculator
Strain measures the deformation of a material relative to its original length. It is dimensionless (a ratio). Engineering strain is defined as the change in length divided by the original length. Positive strain indicates tension (elongation), negative indicates compression. Most engineering materials experience strains well below 1% before yielding. Strain gauges measure this quantity in practice, often in units of microstrain (strain x 10^6).
Frequently Asked Questions
What is the difference between stress and strain?
Stress is the force per unit area applied to a material. Strain is the resulting deformation. They are related by the elastic modulus: stress = E x strain.
What is yield strain?
Yield strain is the strain at which a material begins to deform permanently. For mild steel, this is typically around 0.1-0.2%.
Can strain be negative?
Yes. Negative strain indicates compression (the material is getting shorter), while positive strain indicates tension (the material is getting longer).