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Thermal Expansion Calculator

Estimate one-dimensional thermal expansion or contraction over a temperature change using a constant linear expansion coefficient.

Enter every field, including explicit zeros when permitted. Decimal and scientific notation are accepted; commas, fractions and blanks are rejected. Each input must be finite and no larger than 1 billion in absolute value. Observe the stated units and domain limits.

Length change (m)0.0012
Final length (m)2.0012

How to use this calculator

  1. Enter every quantity in the unit printed beside its field.
  2. Select Calculate or press Enter.
  3. Read the labeled results and compare them with the assumptions below.

Formula and method

Linear expansion ΔL = αL₀ΔT, with the coefficient converted from µm/m·°C to 1/°C.

The calculation runs locally in your browser. If any entry is invalid or a mathematical condition is undefined, the prior result is hidden so it cannot be mistaken for a new answer.

Worked example

Using Initial length (m) = 2, Linear expansion coefficient (µm/m·°C) = 12, Temperature change (°C) = 50, the formula returns Length change (m) = 0.0012, Final length (m) = 2.0012. The displayed default result is generated from these same inputs.

Limitations and safety

Assumes a uniform unconstrained material and constant coefficient. Restraint can create stress; joints and structures require engineering design. Phase changes and temperature gradients are excluded. Results use floating-point arithmetic and are displayed to about 10 significant digits; measurement uncertainty usually supports fewer. Verify units before relying on a result.

Frequently asked questions

Can the length change be negative?

Yes. A negative temperature change produces contraction when the expansion coefficient is positive.

Why might a measured result differ?

The formula isolates the stated model. Real systems can add uncertainty, losses, changing properties, geometry or forces that are not among the inputs.

How should I handle units?

Convert every value to the unit shown beside its field before calculating. A numerically valid value in the wrong unit will still produce a wrong result.

Review notes and reference

Reviewed October 3, 2026. The default example and an independent edge or scaling case were checked against expected values. The live script was also checked for blank, text, comma-formatted, non-finite and out-of-range entries. Method reference. Constants use the values stated in the formula. This page’s explanation and example are original.

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