Thermal Expansion Calculator
Linear thermal expansion estimates how the length of a material changes when its temperature changes, given a linear expansion coefficient.
How to use this calculator
- Enter initial length, coefficient per degree Celsius, and signed temperature change. Negative temperature change represents cooling.
- Check the labels and units before applying the result to a real task.
- Change one input at a time when comparing scenarios.
Formula and method
ΔL = αL₀ΔT; Lfinal = L₀ + ΔL
- ΔL = αL₀ΔT; Lfinal = L₀ + ΔL
- This first-order model assumes the coefficient is suitable for the temperature range and ignores constraints, stress, joints and multidimensional expansion.
Worked examples
Worked example
A 2 m component has α = 12×10⁻⁶/°C and warms by 50°C.
ΔL = 12×10⁻⁶×2×50 = 0.0012 m, or 1.2 mm.
ΔL = 12×10⁻⁶×2×50 = 0.0012 m, or 1.2 mm.
Understanding the result
Linear thermal expansion estimates how the length of a material changes when its temperature changes, given a linear expansion coefficient.
This first-order model assumes the coefficient is suitable for the temperature range and ignores constraints, stress, joints and multidimensional expansion.
Important notes
This first-order model assumes the coefficient is suitable for the temperature range and ignores constraints, stress, joints and multidimensional expansion.
Displayed values are rounded for readability; retain appropriate precision when continuing a calculation.
Frequently asked questions
Can the length change be negative?
Yes. A negative temperature change usually gives a negative length change for a positive expansion coefficient, representing contraction.
Where do I find the expansion coefficient?
Use a reliable specification for the material and relevant temperature range. Different alloys or grades can have different coefficients.
Does this calculate thermal stress?
No. Thermal stress depends on restraints, geometry, elastic properties and boundary conditions, none of which are represented in the simple length estimate.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.