Volume of a Cube

The volume of a cube is the space it takes up in the three-dimensional plane. It is measured in cubic units such as m 3 , cm 3 , mm 3 , ft 3 , or in 3 . The volume of a cube determines how big it is.

Formulas

With Edge Length

The basic or common formula to determine the volume of a cube is:

Let us solve some examples involving the above formula.

Find volume of a 5 x 5 cube.

As we know,
The edge length determines the size of a cube,
Volume (V) = a 3 , here a = 5 units
= 5 3
= 125 cubic units

What is the volume of a 9 inch cube?

As we know,
Volume (V) = a 3 , here a = 9 in
= 9 3
= 729 in 3

Calculate the volume of a 40ft high cube container.

As we know,
The length, breadth, and height of a cube is same,
Volume (V) = a 3 , here a = 40 ft
∴ V = 40 3
= 64000 ft 3

With Diagonal

The formula to get the volume of a cube when the diagonal is known is:

Derivation

Here we will use the equation of the diagonal to derive the formula of volume of a cube with diagonal.

Length of Space Diagonal (d) = $a>$ — (1)

The equation for volume of a cube with edge length is V = a 3 , — (2)

Now, replacing the value of a in eqn (1)

V = a 3 = (d/√3) 3 replacing the value of a from (1)

Calculate the volume of a cube given its diagonal 3 cm.

As we know,
Volume (V) = $>d^>$, here d = 3 cm
∴ V = √3 × 3 3 /9
= 5.2 cm 3

finding the EDGE of a cube when the VOLUME is known

Calculate the side length of a cube given its volume 343 cubic millimeters.

Side length of a cube is actually its edge length. Oftentimes the edge is termed as side length.
So, we will use an alternative formula to find the edge with the volume,
$>$, here V = 343 mm 3
$>$
= 7 mm

Last modified on August 3rd, 2023