How this concrete slab calculator works
Length × width × thickness gives cubic feet. Thickness is converted from inches to feet, waste is added, then volume is divided by 27 to convert cubic feet to cubic yards.
How to use it
- Slab length. Enter the value in ft.
- Slab width. Enter the value in ft.
- Slab thickness. Enter the value in in.
- Waste allowance. Enter the value in %.
- Request the result. Add your email, then select “Email & show my result.”
What to do with the number
Ready-mix concrete is typically ordered by cubic yard, so the purchase figure is rounded upward to a practical tenth of a yard. Do not reduce the thickness just to save material; use the thickness required for the project and local structural conditions.
Planning estimate
Use this result as a starting point, not a guarantee. Product specifications, site conditions, manufacturer guidance, local codes, taxes, labor, tolerances, and rounding can change the real requirement or cost.