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Thermal Expansion Calculator

Calculate linear thermal expansion of a material due to a temperature change, given its coefficient of thermal expansion.

Initial length of the component at reference temperature.
Temperature change in °C. Positive = heating; negative = cooling.
Select material to use its standard thermal expansion coefficient (μm/m·°C).

Results

Length Change (ΔL)0.5,850 mm
New Length1,000.5,850 mm
Length Change %0.0,585%

📖What is it?

Linear thermal expansion describes how a solid material changes in length with temperature. The formula ΔL = L₀ × α × ΔT relates the original length, thermal expansion coefficient (α), and temperature change to the resulting dimensional change. This is critical in mechanical design, structural engineering, and precision manufacturing.

🎯How to use

Enter the original length of the component in mm, the expected temperature change in °C (negative for cooling), and select the material. The calculator uses the standard linear thermal expansion coefficient (in μm/m·°C = 10⁻⁶ m/m·°C) for that material.

💡Example scenario

A 1000 mm carbon steel shaft heats up by 50°C during operation. ΔL = 1000 × (11.7 × 10⁻⁶) × 50 = 0.585 mm. This expansion must be accommodated by tolerances or expansion joints; ignoring it in a constrained assembly would generate significant compressive stress.

🏆Pro tip

Invar (Ni-Fe alloy) has an extremely low α of ~1.2 μm/m·°C — ideal for precision instruments, laser optics mounts, and metrology equipment. Concrete and steel have nearly identical coefficients (~11–12 μm/m·°C), which is why steel-reinforced concrete is so effective — the two materials expand and contract together under temperature cycling.