Linear Thermal Expansion Calculator

About this calculator

Most solids expand when heated and contract when cooled, and for moderate temperature changes this behavior is well approximated by ΔL = α·L0·ΔT, where α is the material's coefficient of linear thermal expansion — roughly 12×10⁻⁶/°C for steel and 23×10⁻⁶/°C for aluminum, for example.

Engineers rely on this relationship to size expansion joints in bridges, railways, and pipelines, to set clearances in machined assemblies, and to predict the stress that builds up when expansion is mechanically constrained. This calculator is used by mechanical and civil engineers, machinists, and physics students working through thermal expansion problems.