Before you lay a cement walkway or driveway on your property, you need to figure out how many cubic yards of cement you're going to need. The cubic yard is a measurement of not only length and width, but of depth as well. You can take the dimensions you want your concrete slab to end up with and convert those numbers into cubic yards with a calculator and a few minutes of your time.
Determine the total thickness, in inches, of the cement slab to be laid. This depends on the type of slab you're laying, the purpose you're laying it for and your own preferences. Divide this number by 12 to convert it from inches to feet.
Measure the length and width of the area that will contain your cement. Find this information in feet.
Multiply the two measurements (length and width) from Step 2 together. Multiply the product by the depth measurement (in feet) from Step 1. The number you get is the total cubic feet of cement you need for your project.
Divide your Step 3 number by 27. There are 27 cubic feet in 1 cubic yard. The number you get is the cubic yards of cement needed to complete your project. For example, if your dimensions multiplied together gave you 1,000 cubic feet, 1,000 divided by 27 equals 37.04 cubic yards of cement.