Created By : Vaibhavi Kumari

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 17, 2023

Thermal Expansion Calculator: When you heat a substance, it expands. It shrinks when you chill it down. But how much is it? The "thermal expansion coefficient" is a material attribute that determines this. This concept is explained in further depth in this article. Continue reading if you want to understand the thermal expansion equation.

Choose a Calculation:
Initial temperature
Final temperature
Initial length
Final length

Choose a Calculation:
Volume expansion coefficient
Initial temperature
Final temperature
Initial volume
Final volume

What is Thermal Expansion?

Every substance is made up of molecules that are packed together more or less densely. When we raise the temperature of a substance, we are actually supplying energy. Obviously, energy does not vanish; it simply transforms into kinetic energy. Molecules with higher kinetic energy start moving around more. You can probably guess that the more they travel, the wider apart they must remain.

Volumetric vs. Linear Expansion

The linear expansion is a one-dimensional expansion. It's most noticeable in objects whose length is substantially greater than their width. A good example is railroad tracks. Have you noticed that the tracks are not continuous, but rather are made up of hundreds of individual parts separated by small gaps (called control joints).

Thermal expansion is the cause of this. A track can be 0.48 % longer during hot summers (40°C) than when the temperature is 0°C. It may not seem like much, but when a track is 1 km long, the difference in length is 48 cm! Of course, this does not imply that the railroad tracks expand just in one direction; we ignore the rise in height and width, which is a multiple of the increase in length and width.

On the other hand, volumetric expansion is a three-dimensional process. If material is isotropic (meaning it has the same qualities in all directions), it expands in the same way in all directions. Consider the following scenario: you're trying to open a closed glass jar with a metal lid. It may be tough at first, but after pouring some hot water on the lid, it will release more easily. Because the lid expanded far quicker than the glass, this happened.

Thermal Expansion Equation

To determine the thermal expansion of any object, our thermal expansion calculator employs a simple formula. The linear and volumetric expansion equations are fairly close.

Linear expansion: ΔL = aL₁(T₂ - T₁)

Volumetric expansion: ΔV = bV₁(T₂ - T₁)

  • where, T₁ = initial temperature
  • T₂ = final temperature;
  • ΔL = change in object's length;
  • L₁ = initial length;
  • a = linear expansion coefficient;
  • ΔV = change in object's volume;
  • V₁ = initial volume; and
  • b = volumetric expansion coefficient

How to Use the Thermal Expansion Calculator?

The following is the procedure how to use the thermal expansion calculator

  • Step 1: In the input field, enter the initial and final temperatures, the length of the material, the material's coefficient of linear expansion, and x for the unknown.
  • Step 2: To acquire the linear expansion, click the "Calculate x" button.
  • Step 3: Finally, the material's thermal expansion will be shown in the output field.

Linear Expansion Coefficient

The rates at which a material expands are measured by its linear and volumetric expansion coefficients. In isotropic materials, these two coefficients are linked: b = 3a. A list of the most frequent linear expansion coefficients may be found below.

  • Aluminium: 22.2×10^-6 1/K
  • Copper: 16.6×10^-6 1/K
  • Concrete: 14.5×10^-6 1/K
  • Ice: 51×10^-6 1/K
  • Glass: 5.9×10^-6 1/K
  • Silver: 19.5×10^-6 1/K
  • Wood, parallel to grain: 3×10^-6 1/K
  • Wood, across (perpendicular) to grain: 30×10^-6 1/K

FAQs on Thermal Expansion

1. What is the definition of thermal expansion in water?

When the temperature of the water rises, thermal expansion causes an increase in the volume (or a decrease in density) of the water.

2. What is an example of thermal expansion?

A change in temperature is linked to thermal expansion. The greater the temperature differential, the greater the expansion of the object. The second point is that it is material-dependent. For example, In a thermometer, the expansion of alcohol is substantially more than the expansion of the glass in which it is contained.

3. What is the thermal expansion coefficient?

The coefficient of thermal expansion is a material property that measures how much a substance expands when heated. The thermal expansion of uniform linear objects is proportional to temperature change over narrow temperature ranges.

4. What does it mean to have a high thermal expansion coefficient?

This coefficient is known as the coefficient of thermal expansion, and it is used to forecast how materials will increase in response to a change in temperature. The higher a material's coefficient of thermal expansion is, the more it will expand when heated.