Few things are as frustrating as having way too much sand delivered or running out of concrete for a project because you mismeasured. A cubic foot can come in many shapes. This tutorial explains how you can easily figure out the cubic feet or cubic yards needed for a project.
Measuring a Cubic Foot
The surface area of a concrete slab or sand base is directly affected by its thickness. In the photo, you see two examples of a measured cubic foot. Since a cubic foot is measured by Length x Width x Thickness, a cube 1-foot long x 1-foot wide x 1 foot thick is therefore 1 cubic foot. As you reduce the thickness, you increase the surface area (LxW) coverage, like cake batter. To determine how many cubic feet you need for a hole, measure the length, width, and thickness together, all measured in feet. So a 4" thickness is 4"/12" or 0.333 feet. The result of this Length x Width x Thickness multiplication is cubic feet. Likewise, a cubic yard (yard = 3 feet) is a cube 3 feet by 3 feet by 3 feet or 27 cubic feet. Here’s a helpful table that shows how surface area changes as thickness varies for one cubic yard (27 cubic feet) of material:
3" Thickness Provides nominal 100 Square Feet of Surface Area4" Thickness Provides nominal 81 Square Feet of Surface Area5" Thickness Provides nominal 65 Square Feet of Surface Area6" Thickness Provides nominal 55 Square Feet of Surface Area8" Thickness Provides nominal 40 Square Feet of Surface Area
