MasterTool

Thermal Expansion Calculator

Calculate thermal expansion instantly in your browser — the published formula, worked locally with no data sent anywhere.

Handbook linear-expansion coefficients last updated · Engineering handbook tables (Machinery's Handbook values)

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Dated static reference; no live data is fetched. Verify current source values and assumptions before relying on results.

What this tool does

Calculate thermal expansion instantly in your browser — the published formula, worked locally with no data sent anywhere. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.

How to use the Thermal Expansion Calculator

  1. Enter or select material.
  2. Enter or select custom α (per °c).
  3. Enter or select original length in ft.
  4. Enter or select temperature change δt (°c, + warms / − cools).
  5. Read the calculated result; change any measurement to compare alternatives.

Formula

linear expansion ΔL = α × L × ΔT, with α the material's coefficient of linear expansion per °C (handbook values near room temperature).
material
Material
alpha
Custom α (per °C)
length
Original length (ft, before metric conversion)
dT
Temperature change ΔT (°C, + warms / − cools)

α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.

Worked example

For thermal expansion calculator, the following measurements illustrate the exact method: Material: 0.000012; Custom α (per °C): 0.000012; Original length: 10; Temperature change ΔT (°C, + warms / − cools): 50.

Inputs

  • MaterialSteel (carbon)
  • Custom α (per °C)0.000012
  • Original length10 ft
  • Temperature change ΔT (°C, + warms / − cools)50

Result

  • Change in length (mm)1.83
  • Change in length (in)0.07
  • New length (ft)10.01
  • Coefficient used (per °C)0
  • Strain (ΔL/L)0

Results explained

Change in length (mm)
Change in length (mm) from the formula above. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.
Change in length (in)
Change in length (in) from the formula above. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.
New length (ft)
New length (ft) from the formula above. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.
Coefficient used (per °C)
Coefficient used (per °C) from the formula above. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.
Strain (ΔL/L)
Strain (ΔL/L) from the formula above. α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.

Frequently asked questions

linear expansion ΔL = α × L × ΔT, with α the material's coefficient of linear expansion per °C (handbook values near room temperature).

α is treated as constant over the temperature range; real coefficients drift slightly with temperature. Area expansion is approximately 2α and volume expansion 3α for isotropic solids — which is why expansion gaps in bridges and rails are sized with this formula.

Every field is labelled with its unit — enter values in exactly the labelled unit and read the result in the labelled output unit. Fields with a unit symbol also support the site-wide imperial/metric switch, which converts before the formula runs.

It uses double-precision arithmetic and the published constants and formulas named on this page. The last displayed digit may be rounded, and real conditions can differ from the idealized model described in the assumptions.

Yes. Every calculation runs entirely in your browser; nothing you enter is uploaded, stored or shared.