How Find the Cubic Feet in a Tube

Sometimes it is necessary to calculate the number of cubic feet in a tube. Because the words "cubic feet" denote squares and tubes are circular, it requires a bit of math to figure this out. This is relatively easy to do and requires only the measurements of the tube and a calculator.

Significance

The formula for the area of a tube is pi times the radius squared times the height. Pi is the ratio of a circle's circumference to its diameter and is 3.14. So, if a tube is 10 feet high and 2 feet across (= radius of one foot), the area is 314 feet cubed.

Features

Cubic feet is a different measurement than square feet. Cubic feet refers to an area in three dimensions (length, width, height) whereas square feet refers to an object in two dimensions (length and width).

Size

When working with measurements, it is always important to keep the units the same. For instance, in the earlier example, if we were to asked to figure out the cubic inches rather than the cubic feet, we would need to multiply each measurement by 12. Then, the answer would have been 54,259 cubic inches.

Considerations

There are some materials that are sold by the cubic foot, so it is important to be able to calculate how much of these materials are needed before pursuing a home improvement job. For instance, concrete for repairing driveways and making columns (which are essentially tubes) can be purchased in cubic feet. Sand and mulch are often calculated in a similar manner.

Prevention/Solution

It is also possible to measure the total number of cubic feet in a small tube, but the number will be quite small. In these cases, it may be advantageous to convert the volume from cubic feet to a smaller measurement such as cubic inches or cubic centimeters.