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📏 Thermal Expansion Calculator

Find out how much longer a rod, rail, pipe, or beam becomes when it heats up, based on its material’s linear expansion coefficient.

m
°C

What This Calculator Does

Most solid materials expand slightly when heated and contract when cooled. This calculator estimates how much a straight length of material — a rail, pipe, beam, or rod — grows or shrinks for a given temperature change.

The Formula

Linear thermal expansion is calculated as ΔL = L₀ · α · ΔT, where L₀ is the original length, α is the material’s coefficient of linear thermal expansion (per degree Celsius), and ΔT is the temperature change. Each material has its own characteristic α value, reflecting how strongly its atomic bonds respond to heat.

Note: This is a linear approximation valid over normal engineering temperature ranges, for general educational and planning purposes. Real materials can behave non-linearly near phase transitions or extreme temperatures, and actual coefficients vary by alloy and manufacturing process.

Last reviewed August 2026