How to Calculate the Concrete for Foundation

Concrete is sturdy and provides an excellent foundation for a home.

Concrete is one of the basic building materials in modern construction. It is used for walls, floors, foundations, fences and walkways. Concrete is a mixture of cement, aggregate, water and various chemicals. The foundation of a building supplies the support for the entire structure. When pouring concrete for the foundation, there are various elements you need to consider, such as the structural integrity of the soil and the local building codes. You should consult a professional contractor to make sure that your foundation will be safe and up to building codes.

Things You'll Need

• Foundation plan
• Measuring tape

Instructions

1. Outline your foundation so that you know the dimensions. You can use plastic tape, flags, wood, paint or chalk.

2. Measure each side of your foundation with your measuring tape. If the foundation is not a basic shape, such as a square, rectangle or triangle, then separate it into a collection of those shapes. Then measure the sides of each of these smaller shapes with a measuring tape.

3. Calculate the cubic feet of each of the shapes and then add all of the cubic feet together to determine the total cubic feet of the foundation. To find the areas and volumes of basic geometric shapes, visit the website in the references section.

4. Convert your total cubic feet to cubic yards by dividing by 27. For example, if you have 54 total cubic feet, then you will have 2 total cubic yards.

5. Determine the number of bags of concrete that you will need. For every cubic yard of space you need to fill, you will need 90, 40 pound bags of concrete. Use that to determine the number of bags you will need. For example, if you have 1.5 cubic yards of space, and you use 40 pound bags of concrete, then you will need 135 bags of concrete.

References

• Lake Tahoe Community College: Basic Shapes