How to Calculate the Cubic Feet for a Mixer

Determine the amount of concrete necessary to complete your job using some simple math.

Whenever you want to tackle a project that requires concrete, such as laying the foundation for a shed or extending your patio, you need to know exactly how much concrete mix the job requires. Depending on the amount of concrete needed, you may choose to rent or purchase a concrete mixer, which eases and automates the mixing of the concrete. First determine the number of cubic feet of concrete needed for the job.

Things You'll Need

• Tape measure
• Calculator

Instructions

1. Measure the length, width and height of the area that you will concrete.

2. Convert any units not measured in feet to feet. For example, if you are concreting an area that is 10 feet long by 12 feet wide, with a height of 4 inches, convert the height, which was measured inches, to feet by dividing the number of inches by 12. In this example, divide 4 by 12, which amounts to .25 feet.

3. Multiply the length times the width times the height to determine the number of cubic feet of concrete needed to complete the job. For example, if the area to be concreted is 10 feet long, 12 feet wide and .25 feet tall, the job would require 30 cubic feet of concrete.

Tips & Warnings

• If the shape of the area to be concreted is irregular, break the sections into squares and determine the cubic footage of each square, then add the squares together to obtain the total number of cubic feet needed.

References

• Janss Lumber: Calculating Cubic Feet