Cubic feet: Definition, conversion, and examples

Cubic feet is a quantity that is very popular in the construction field, generally, civil engineers use this term in their daily work routine. If you know how to find the area of any rectangular shape like a cube, or room by using the length and width of that specific shape then you are one step far from understanding a way to calculate cubic feet.      

Cubic feet-  Definition, conversion, and examples
Cubic feet- Definition, conversion, and examples

Further in this article, we will study the basic introduction and the calculation principles of cubic feet for more assistance we will tally the example section.

What is a cubic foot?

A cubic foot (cu ft. or cubic ft.) is an imperial unit of dimension for the quantity of an area or 3-dimensional item. Professionals normally use cubic feet, cubic yards, and cubic meters in creation and landscaping initiatives to locate the overall quantity of fill materials, like dust or concrete, they may want to finish a task.

For instance, while pouring concrete, you must have to calculate cubic feet to decide the quantity of concrete you want to reserve given that cubic feet are the same old unit of quantity for this cloth. It is a unit of volume.

A cubic foot is not only related to cubes, it actually contains 3 equal dimensions. If a cube has a length, width, and height of 1 foot then its volume will be equal to 1 cubic foot.

The formula for calculating the cubic foot:

If you have the values in feet then the formula is quite simple and easy to remember, it is just like the formula of volume.

Cubic feet (volume) = Length (ft.) * Width (ft.) * height (ft.)  

This formula is generally used to calculate the volume of the bodies that must have noticeable dimensions we can’t use this formula for spheres and cones etc.

How to calculate cubic feet?

To calculate cubic feet, there are two different scenarios. The first one is that if the values are given in feet then we just have to apply the above formula, but if the values are not given in feet then we should have to follow some extra steps for calculation, the steps are as follows:

  • Convert all the values into feet
  • Put the converted values into the formula.
  • Multiply the values and get the answer.

In this section, we will discuss both scenarios of calculating the volume in cubic feet.

Scenario 1:

We will discuss the problems in which the parameters are given in feet.

Example 1:

Calculate the volume of a carton that has a height of 4 feet, a length of 6 feet, and a dimension of 2.5 feet.


Step 1: Write down the given data of the above example.

Given data: 

Length = 6 feet           

Dimension = Width = 2.5 feet

Height = 4 feet

Step 2: Putting values in the above formula

Volume = Length (feet) * dimension (feet) * Height (feet)

Volume = (6) * (2.5) * (4)

 Volume = 60 ft3

Example 2:

Calculate the volume of the room if its measurements are height = 15 ft., Length = 15 ft., and dimension = 15 ft.


Height= 15 ft. 

Length= 15 ft.

Width= 15 ft. 


Volume (Cubic feet) = Length (feet) * dimension (feet) * Height (feet)

Volume = 15 ft. * 15 ft. * 15 ft. 

 Volume = 3375 ft3  

Scenario 2:

If the given parameters are not in feet.

Example 1:

A 3D cube has height = 2.5 meter, width = 2 meters, length = 3 meter, what will be its volume?


Step 1: Write down the given information.

Given data:

Length = 2.5 meters

Width = 2 meters 

Height = 3 meters  

Step 2: Convert the given data into feet.

To calculate the volume in cubic feet we should have to convert the data into feet.

 Multiply the given data by “3.281” for converting it into feet.

Length= 2.5 * 3.281 = 8.203 ft.

Width= 2 * 3.281 = 6.562 ft.

Height= 3 * 3.281 = 9.843 ft.


Volume (Cubic feet) = Length (feet) * dimension (feet) * Height (feet)

Step 3: Putting values in the formula.

Volume = Length (feet) * dimension (feet) * Height (feet)

Volume = 8.203 * 6.562 * 9.843

Volume = 529.830 ft3

Alternative method:

Step 1:

Length = 1 meters

Width = 1.5 meters 

Height = 2 meters 


Length (meters) * width (meters) * height (meters) * 35.315 = answer (cubic feet)

Step 2: Put the values in the above formula

Volume = 1 * 1.5 * 2 * 35.315

Volume = 105.94 ft3

Example 2: Evaluate the volume in cubic feet of a rectangle of the following dimensions.

Width = 10 meters

Length = 12 meters

Height = 14 meters


By using the usual volume formula, you will get the result in cubic meters. So to calculate in cubic feet.

Step 1: Convert the meters to feet.

As 1 meter = 3.281 feet

Length = 12 m = 12 * 3.281 feet = 39.372 ft

Height = 14 m = 14 * 3.281 feet = 45.934 ft

Width = 10 m = 10 * 3.281 feet = 32.81 ft

Step 2: Multiply the values according to the cubic feet formula.

= L * H * W

= 39.372 * 45.934 * 32.81

= 59337.33 ft3


In this article, we have studied the main purposes and uses of a cubic foot. We have also described the basic introduction of this term. Moreover, we have elaborated on the calculations and the conversions of different units, and we have provided a detailed concept of how to convert other units into cubic feet.

In the example section, we practically explained the theory of conversion, hope this article will help you a lot in calculating and converting the volume in cubic feet.