B2B Agency Live AI

Concrete calculator for slabs, footings, and columns

Enter your dimensions to estimate cubic yards, plus the number of 60 lb and 80 lb bags. The calculator updates instantly and is designed for easy use on phones and tablets.

Choose a concrete shape

Length

Width

Thickness

Concrete neededSlab volume

0.00 cubic yards

0.00 cubic feet

Estimated bagsRounded up

0 bags of 60 lb

0 bags of 80 lb

Length

Width

Depth

Concrete neededFooting volume

0.00 cubic yards

0.00 cubic feet

Estimated bagsRounded up

0 bags of 60 lb

0 bags of 80 lb

Diameter

Height

Concrete neededColumn volume

0.00 cubic yards

0.00 cubic feet

Estimated bagsRounded up

0 bags of 60 lb

0 bags of 80 lb

Quick reference

Slab formula Length × width × thickness ÷ 12 to get cubic feet, then ÷ 27 for cubic yards.

Footing formula Length × width × depth ÷ 12 to get cubic feet, then ÷ 27 for cubic yards.

Column formula Use a round column: π × radius² × height for cubic feet, then ÷ 27 for cubic yards.

Bag estimates 60 lb bag ≈ 0.45 cu ft, 80 lb bag ≈ 0.60 cu ft. Rounded up so you can order enough concrete.

Tip: Add a little extra concrete for waste, spills, and uneven subgrade.