This thermal expansion calculator finds the change in length of a material when heated or cooled, using ΔL = α × L × ΔT.
Thermal Expansion Calculator
Formula
ΔL = α × L × ΔT
How to Use This Calculator
- Enter the original length in metres.
- Enter the coefficient of linear expansion (e.g. steel ≈ 0.000012 /°C).
- Enter the temperature change and click Calculate.
Worked Example
A 10 m steel rail (α = 1.2×10−5/°C) heated by 50°C expands by ΔL = 0.000012 × 10 × 50 = 0.006 m (6 mm).
Frequently Asked Questions
What is the formula for linear thermal expansion?
Change in length dL = alpha x L x dT, where alpha is the coefficient of linear expansion, L the original length and dT the temperature change.
What is the coefficient of thermal expansion of steel?
About 12 x 10^-6 per degree Celsius (0.000012 /C).
Why do materials expand on heating?
Heating increases the vibration of atoms, increasing their average spacing, so the material expands.