Thermal Expansion Calculator – Linear and Volumetric Expansion

Calculate how much a material expands or contracts with temperature change. Our thermal expansion calculator covers linear and volumetric expansion for engineering design.

Expansion Type

Material

Coefficient α (1/°C)

Original Length (m)

Temp Change ΔT (°C)

How It Works

Select Expansion Type

Choose between linear expansion (length change) or volumetric expansion (volume change) for your application.

Enter Material & Dimensions

Select from common materials or enter custom coefficient, original length, and temperature change.

Get Expansion Results

See the change in dimension and final dimension after thermal expansion or contraction.

Thermal Expansion Coefficients Reference

Material	Coefficient α (1/°C)	Expansion per 100°C (per meter)
Aluminum	23 × 10⁻⁶	2.3 mm
Steel	12 × 10⁻⁶	1.2 mm
Copper	17 × 10⁻⁶	1.7 mm
Brass	19 × 10⁻⁶	1.9 mm
Concrete	12 × 10⁻⁶	1.2 mm
PVC	52 × 10⁻⁶	5.2 mm

Key Features & Benefits

Linear & Volumetric Modes

Calculate both linear expansion (ΔL = αLΔT) and volumetric expansion (ΔV = βVΔT where β = 3α).

Pre-loaded Materials

Quick selection of common engineering materials with accurate thermal expansion coefficients.

Custom Coefficient Support

Enter custom thermal expansion coefficients for specialized materials not in the database.

Engineering Applications

Essential for bridge design, pipeline engineering, rail gaps, and precision instrument calibration.

Frequently Asked Questions

What is thermal expansion?

Thermal expansion is the tendency of matter to change in size when temperature changes. Most materials expand when heated and contract when cooled. This is critical in engineering to prevent structural damage from temperature variations.

What is the formula for linear thermal expansion?

ΔL = α × L₀ × ΔT, where ΔL is change in length, α is the coefficient of linear expansion, L₀ is original length, and ΔT is temperature change. For volumetric expansion: ΔV = β × V₀ × ΔT where β ≈ 3α.

Why do bridges have expansion joints?

Bridges expand in summer heat and contract in winter cold. A 100m steel bridge can change length by 12cm between -20°C and +40°C. Expansion joints accommodate this movement without causing structural damage.

Which material expands the most?

Among common engineering materials, plastics like PVC (52 × 10⁻⁶/°C) expand the most, followed by aluminum (23 × 10⁻⁶/°C). Metals generally expand more than ceramics and glass. Invar alloy has near-zero expansion.

Does water expand when heated?

Water behaves unusually – it contracts when heated from 0°C to 4°C, then expands above 4°C. This is why ice floats and lakes freeze from the top down. Water's expansion coefficient varies significantly with temperature.

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