Estimate concrete volume for rectangular slabs, including quantity and a configurable waste allowance.
This version is for rectangular slabs. Length and width are in feet; thickness is in inches.
Convert slab thickness from inches to feet, then multiply length × width × thickness × quantity. The waste percentage is applied after the geometric volume is calculated.
Concrete is commonly ordered by cubic yard or cubic meter. A waste allowance can cover uneven excavation, spillage and small dimensional variation, but the appropriate percentage depends on the job.
There are 27 cubic feet in one cubic yard.
Built dimensions are rarely perfect. Waste can also account for spillage and irregular surfaces, but the appropriate allowance depends on the project.
No. It uses an approximate 0.60 cubic feet per 80-lb bag. Always check the bag manufacturer’s published yield.