Free · Physics models
Poisson Ratio from Strain Magnitudes
Calculate the nonnegative Poisson ratio from contraction and extension strain magnitudes, or relate isotropic elastic moduli.
- Formula & worked example
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Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
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Formula and method
Poissons ratio = 0.30000000; shear modulus = 76.923077 GPa.
ν = |transverse contraction strain| / |axial extension strain|; E = 2G(1+ν).
Worked example
Enter these known values and leave the other values blank.
- Transverse contraction strain magnitude
- 0.003
- Axial extension strain magnitude
- 0.01
- Modulus of elasticity (E)
- 200 GPa
- Shear modulus (G)
- 76.923 GPa
- Poisson's ratio (v)
- 0.3
Assumptions and limitations
- Calculate the nonnegative Poisson ratio from contraction and extension strain magnitudes, or relate isotropic elastic moduli.
- Use magnitudes for conventional tensile extension with lateral contraction. This control convention omits the minus sign used with signed transverse strain.
- The supported ratio is zero through 0.5. Auxetic negative ratios are outside this calculator. E = 2G(1+ν) assumes isotropic linear elasticity and small strain.
- Inputs and inverse outputs share the displayed unit selectors. Clear a known field to solve for it, and lock quantities that must remain fixed. Singular inverses may have no finite result.
Common questions
Can I enter signed lateral contraction?
Enter its positive magnitude here. The usual signed definition is minus lateral strain divided by axial strain.
Can this model auxetic materials?
The retained range excludes negative Poisson ratios.
References
Enforce the explicitly stated physical domain: Axial extension strain magnitude must be positive. Transverse contraction magnitude cannot be negative. Young modulus must be positive. Shear modulus must be positive.