How much mixed concrete for 10ftx10ft square 4 inch thick area?

Answer 1

10 x 10= 100, but divide by 3. 4 inches is one third of a foot. You need 33 and a third cubic feet of concrete. Mixed concrete is usually sold in cubic yards (3 ft x 3ft x3 ft- or 27 cu ft to a cubic yard) and you would need ABOUT 1.25 yards. If you want to mix your own by buying prepackaged concrete mix at the hardware store, you would need ABOUT 112 of the 40 pound bags, or ABOUT 56 of the 80 lb bags. See the link below for a handy calculator for home concrete. PS- sound like you might be pouring a patio or floor for a small shed. Be sure to use reinforcing wire mesh in the floor, or it may crack.