Thermal Expansion Calculator
Calculate linear expansion from length, coefficient and temperature change.
Formula
ΔL = αL₀ΔT.
What Is Linear Thermal Expansion?
Most materials change length when their temperature changes. Linear thermal expansion estimates that change using the original length, the material’s linear expansion coefficient and the temperature difference.
Example Calculation
A 2 m steel bar with α = 12 × 10⁻⁶ /°C heated by 50°C expands by 12×10⁻⁶ × 2 × 50 = 0.0012 m, or 1.2 mm.
Factors and Interpretation
Longer objects, larger temperature changes and materials with higher expansion coefficients produce greater length changes. A negative temperature change gives contraction. The simple linear formula assumes the expansion coefficient remains approximately constant over the temperature range.
Frequently Asked Questions
Can ΔT be entered in kelvin?
Yes. A temperature difference has the same numerical size in kelvin and degrees Celsius.
Why do bridges use expansion joints?
They allow structures to expand and contract without building excessive thermal stress.
Does every material have the same coefficient?
No. Thermal expansion coefficients vary substantially among metals, glass, polymers and other materials.
Related Tools
Formula and Practical Limits
Linear thermal expansion is commonly ΔL = αL₀ΔT. The coefficient α depends on material and can vary with temperature, so the simple model is best for moderate temperature ranges and unconstrained materials.