How much concrete i need for a slab ?

In this article, we will discuss how much concrete I need for a slab.

To calculate how much concrete will be required for the slab, divide the total cubic yards or cubic feet required by the yields.

In the United States, based on the Imperial and US customary measurement systems, 1 cubic yard is a unit of measurement of the volume given as 3 feet long by 3 feet wide by 3 feet in depth 3’×3’×3′ = 27 cubic feet, so 1 cubic yard is equal to 27 cubic feet.

Note: As we already know concrete bags available in the market are 40 lb, 60 lb, 80 lb, and 90 lb. A 40lb bag of concrete covers about 0.011 cubic yards / 0.30 cubic feet. 60 lb bag of concrete covers about 0.017 cubic yards / 0.45 cubic feet. 80 lb bag of concrete covers about 0.022 cubic yards / 0.60 cubic feet and a 90 lb bag of concrete covers about 0.025 cubic yards / 0.68 cubic feet.

  1. How Much Concrete I Need for a Slab?  

For 4 inches thick slab

To calculate the how much concrete I need for a 7×6 slab in the following ways:-

Step 1:- At first we need to calculate the volume in cubic feet. We have given a 7×6 slab (length × width), consider it is 4 inches thick, 4 inches = 0.33 feet, to calculate the volume of the slab, you should multiply the length, breadth, and height dimensions, such that = 7′×6′×0.33′ = 13.86 cubic foot.

Step 2:- Changing cubic feet into the cubic yards:-

Now changing into the cubic yard, you should divide it by 27, because 1 cubic yard = 27 cubic feet, so the volume of concrete you needed for a 7×6 slab at 4 inches thick in cubic yard

= 13.86/ 27

= 0.51 cubic yards.

Step 3:- Add 10% extra:- Taking extra 10% wastage during mixing and flowing.

Step 4:- No. of bags of 80 lb concrete = 13.86 ÷ 0.60

= 24 bags,

No. of bags of 60 lb concrete = 13.86 ÷ 0.45 = 31 bags,

and No. of bags of 40 lb concrete = 13.86 ÷ 0.30 = 47 bags.