What is the Thermal Expansion Calculator?
Calculate linear, area, and volume thermal expansion with this free thermal expansion calculator. Find ΔL = αL₀ΔT, ΔA = 2αA₀ΔT, and ΔV = 3αV₀ΔT from coefficient of thermal expansion and temperature change. Bimaterial gap mode finds differential expansion between two materials in a sleeve or composite. Results in m, mm, ft, strain, and percent change. Steel, aluminum, concrete, and copper presets. Metric and imperial units. Runs instantly in your browser.
How to use the Thermal Expansion Calculator
- Choose Linear, Area, Volume, or Bimaterial Gap expansion mode.
- Select metric or imperial units.
- Enter original length, area, or volume and temperature change (positive for heating, negative for cooling).
- Enter α in ×10⁻⁶/°C or ×10⁻⁶/°F, or use a material preset.
- Review expansion, final dimension, thermal strain, and copy calculation steps.
Common use cases
- Estimating bridge or rail expansion gap for temperature swings
- Sizing clearance for a steel shaft in an aluminum housing
- Calculating concrete slab area growth from summer heat
- Finding thermal strain for structural design checks
- Materials science homework on CTE and expansion
Frequently asked questions
- What is the formula for linear thermal expansion?
- ΔL = αL₀ΔT, where α is the coefficient of linear thermal expansion, L₀ is original length, and ΔT is temperature change. Final length L = L₀(1 + αΔT).
- What units is α usually given in?
- Engineering tables often list α in ×10⁻⁶ per °C or per °F. Steel is about 12 ×10⁻⁶/°C (6.5 ×10⁻⁶/°F); aluminum about 23 ×10⁻⁶/°C.
- How are area and volume expansion related to α?
- For isotropic materials, area expansion coefficient β ≈ 2α and volume coefficient γ ≈ 3α. So ΔA = 2αA₀ΔT and ΔV = 3αV₀ΔT.
- What is bimaterial differential expansion?
- Two materials with different α bonded or fitted together expand by different amounts: ΔL₁ − ΔL₂ = L₀ΔT(α₁ − α₂). This drives thermal stress or required clearance in shafts, rails, and bridges.
- How is this different from the strain calculator thermal mode?
- The strain calculator gives engineering strain ε = αΔT. This thermal expansion calculator computes actual dimensional changes (mm, m, ft), final sizes, area/volume expansion, and bimaterial gaps.
