Discover how much materials expand or contract with heat. Calculate changes instantly and avoid costly errors with this essential engineering tool.
Quick tip: You don’t need to be an engineer to use this tool—just follow the simple steps below.
Thermal expansion is the phenomenon where materials change in size due to temperature changes. As temperature increases, atomic vibrations intensify, increasing the average distance between atoms and causing expansion. Conversely, materials contract when cooled.
Linear Expansion: ΔL = α × L₀ × ΔT
Area Expansion: ΔA = 2α × A₀ × ΔT
Volumetric Expansion: ΔV = 3α × V₀ × ΔTSteel expansion joints on a 300m bridge with ±30°C variation:
α = 12×10⁻⁶/°C
ΔL = α × L₀ × ΔT = 12×10⁻⁶ × 300 × 30 = 108mmPVC pipes (α = 70×10⁻⁶/°C) in 10m system exposed to ±20°C:
ΔL = 70×10⁻⁶ × 10 × 20 = 14mmStart calculating now to avoid guesswork and build smarter with every degree of change.
| Material | Coefficient (α) | 10m Bar @ +50°C | Formula Used |
|---|---|---|---|
| Aluminum | 23×10⁻⁶/°C | +11.5mm | ΔL = 23×10⁻⁶ × 10 × 50 |
| Glass | 9×10⁻⁶/°C | +4.5mm | ΔL = 9×10⁻⁶ × 10 × 50 |
| Stainless Steel | 17×10⁻⁶/°C | +8.5mm | ΔL = 17×10⁻⁶ × 10 × 50 |
| Concrete | 10×10⁻⁶/°C | +5.0mm | ΔL = 10×10⁻⁶ × 10 × 50 |
| Paraffin Wax (Phase Change) | N/A | ~5% volume jump | Empirical; expansion not linear |
| Carbon Fiber Composite | 0 to -1×10⁻⁶/°C (anisotropic) | Negligible / directional | Depends on fiber layup |