Concrete Slab Calculator

Use this calculator to estimate how many cubic yards of concrete you need for a flat slab. Simply enter the width, length, and depth of your project.

Enter Dimensions

feet
feet
inches

How It Works

  1. Enter the slab's width and length in feet
  2. Enter the slab's depth in inches
  3. The calculator converts the depth from inches to feet
  4. Calculates the volume in cubic feet (width × length × depth)
  5. Converts the volume to cubic yards (cubic feet ÷ 27)
Formula: (Width × Length × Depth/12) ÷ 27 = Cubic Yards

Tips & Notes

  • Add 5-10% extra concrete to account for spillage and uneven ground
  • For irregularly shaped slabs, break the area into regular shapes and calculate each separately
  • Standard concrete slab depths are typically 4" for walkways, 6" for driveways, and 8" for heavy load areas
  • Consider using a thicker slab for regions with freeze-thaw cycles or poor soil conditions