Is the coefficient constant at all temperatures?

No. The listed values are representative. Use temperature-dependent supplier data for wide temperature ranges or critical designs.

Can this calculator be used for pipes?

Yes for free axial movement. Piping stress and support reactions require a flexibility or code analysis.

Why is the restrained stress so high?

Fully preventing thermal strain can create very large elastic stress. Real systems are normally designed to move or flex.

Does wood expand the same in every direction?

No. Wood is strongly anisotropic; movement across the grain is much larger than along the grain.

Drawing No. EH–GE–011 // General Engineering

Thermal Expansion Calculator

Reviewed August 2026

Estimate expansion or contraction from temperature change using a large material library, with optional restrained thermal-stress screening.

Scope: Use representative coefficients for education and preliminary design. Verify the actual grade, orientation and temperature-dependent property before final design.

What problem does this solve?

Estimate how much a bar, pipe, rail, slab or component grows or shrinks as its temperature changes. The material library includes metals, polymers, glass, ceramics, stone, composites and wood.

1. Select materialChoose the closest material or enter your own coefficient.

2. Enter sizeUse the original length at the starting temperature.

3. Enter temperaturesThe sign of the temperature change determines expansion or contraction.

4. Read movementCheck total movement and optional restrained stress.

Inputs

Material coefficient library

Coefficients are representative room-temperature values. Real coefficients vary with grade, direction and temperature.

Linear expansion coefficient α µm/m·K

Original length m

Starting temperature °C

Final temperature °C

Elastic modulus, optional GPa

Used only to estimate fully restrained thermal stress, σ = EαΔT.

Enter a positive length and valid material coefficient.

Results

Temperature change

—

Linear strain

—

Length change

—

Final length

—

Area change, isotropic estimate

—

Fully restrained stress

—

The left end is held as a visual reference. The movement is magnified so expansion or contraction is easy to see; geometry is not to scale.

—Original length

—Final length

—Movement

—Temperature change

Background

How to interpret the model and its limitations.

Frequently asked questions

Practical questions about inputs, assumptions and interpretation.