How many bags of concrete do I need for a 2×2 Slab

how to calculate bags of concrete 

It depends on the thickness and square footage of the slab.


Calculate square footage

Calculate Square footage of the Slab For 2x2 slab  length x width (2x2) = 4 square feet.

Square footage of 2x2 slab 

let us assume that thickness of the slab is 4 inches Square footage of 2x2 slab = 4 sqft.

Calculate volume of slab

Choose 40lb, 60lb or 80 lb bag

40 lb bag yield = 0.30 cubic feet 60lb bag yield = 0.45 cubic feet 80 lb bag yield = 0.60 cubic feet let us choose 60 lb bag having yield of 0.45 cubic feet

No. of bags = vol. of slab/ yield of 1 bag vol. of 2x2 slab= 1.33 cubic feet yield of 60lb bag = 0.45 no. of bags = 1.33/0.45 = 2.95 thus you will need 3 bags for 2x2 feet concrete, 4 inch thick.

Calculate number of bags

2x2 feet slab 4 inch thickness,  60lb bag requires 3 bags