How much concrete do i need for a 30×30×4 slab | how many yards of concrete do I need for a 30×30×4 slab | how many bags of concrete do I need for a 30×30×4 slab | how much concrete do i need for a 30×30 slab at 4″, 5″ and 6″ thick.

Concrete ready mix made of blended mix of Portland cement, sand gravel and other approved ingredient, generally, dry ready mix concrete are available in different bag size and weight condition like 40lb, 60lb bag, 80lb bag, 90lb bag and etc.

Regardless of size you need to calculate the volume of concrete in cubic yard before ordering the mixed concrete. Volume is calculated by multiplying length, width and depth of slab. In this article we have to calculate required quantity of concrete in cubic yard for a 30×30 (900 sq ft) slab at 4 inch, 5 inch or 6 inch thick.

Generally standard thickness of slab is 4 inch thick in normal conditions, if 30×30 slab have heavy traffic and heavy load, you should take depth 5 or 6 inch thick.

Weight of Ready mix concrete in dry condition is about 133 lbs per cubic foot, 3600 lbs per cubic yard, or 2136 kg per cubic meter. The weight of concrete is determined by its density, which can vary based on the amount of aggregate, water, and air in the mix.

In United States, based on Imperial and US customary measurement system, 1 cubic yard is unit of measurement of volume represented by 3 feet long by 3 feet wide by 3 feet depth (3’×3’×3′ = 27 cubic feer), so 1 cubic yard is equal to 27 cubic feet.

**How many yards of concrete do I need for a 30×30×4 slab**

**At 4 inches thick**

To determine the how much concrete do I need for a 30×30×4 slab solve in following steps:-

Step 1 :- calculate the volume in cubic feet:- we have given 30×30 slab (length × width), consider it is 4 inch thick, 4 inch = 0.33 feet, to determine the volume of slab, you need to multiply all dimensions, such that = 30′×30′×0.33′ = 297 cubic foot.

Step 2 :- converting cubic feet into cubic yard:- now converting into cubic yard, you should divide it by 27, because 1 cubic yard = 27 cubic foot, so volume of concrete you needed for 30×30 slab at 4 inch thick in cubic yard = 297/27 = 11 cubic yard.

Step 3 :- Add 10% extra :- considering extra 10% wastage during mixing and pouring, so 10% of 11 cubic yard = 1.1, add 11 + 1.1 = 12.1 cubic yard.

**How much concrete do i need for a 30×30×4 slab**

For a 30×30×4 slab, generally, you will need 11 cubic yards or 297 cubic feet or either 660- 60lb or 495- 80lb or 990- 40lb bags of premixed concrete. Always you should purchase 5 to 10% more premixed than required.

**How many yards of concrete do I need for a 30×30×4 slab**

For a 30×30×4 slab, generally, you will need approximately 11 cubic yards of premixed concrete. Math’s calculation:- 1) square footage of slab = 30×30 = 900 sq ft, 2) 4″ thickness in inches = 4÷12 = 0.33 feet, 3) volume of slab in cubic feet = 900×0.33 = 297 cubic feet, and 4) volume of slab in cubic yards = 297÷27 = 11 cubic yards. Thus, you will need 11 cubic yards of premixed concrete for a 30×30 slab at 4 inches thick.

**How many cubic feet of concrete do I need for a 30×30×4 slab**

For a 30×30×4 slab, generally, you will need approximately 297 cubic feet of premixed concrete. Math’s calculation:- 1) square footage of slab = 30×30 = 900 sq ft, 2) 4″ thickness in inches = 4÷12 = 0.33 feet, 3) volume of slab in cubic feet = 900×0.33 = 297 cubic feet. Thus, you will need 297 cubic feet of premixed concrete for a 30×30 slab at 4 inches thick.

**How many bags of concrete do I need for a 30×30×4 slab**

To determine how many bags of concrete you will need, divide the total cubic yards or cubic feet needed by the yields.

We know concrete bag available in 40lb, 60lb, 80lb and 90lb. 40lb bag of concrete yields about 0.011 cubic yards or 0.30 cubic feet.60lb bag of concrete yields about 0.017 cubic yards or 0.45 cubic feet. 80lb bag of concrete yields about 0.022 cubic yards or 0.60 cubic feet and 90lb bag of concrete yields about 0.025 cubic yards or 0.68 cubic feet.

For a 20×20×4 slab, generally, you will need

either 660- 60lb or 495- 80lb bags of premixed concrete. Math’s calculation:- 1) square footage of slab = 30×30 = 900 sq ft, 2) 4″ thickness in inches = 4÷12 = 0.33 feet, 3) volume of slab in cubic feet = 900×0.33 = 297 cubic feet, and 4) No. of 60lb bags = 297÷0.45 = 660 bags, no. of 80lb bags = 297÷0.60 = 495 bags. Thus, you will need either 660- 60lb or 495- 80lb bags of premixed concrete for a 30×30 slab at 4 inches thick.

**How many yards of concrete do I need for a 30×30 slab at 5″ thick**

At 5″ thick, for a 30×30 slab, generally, you will need 14 cubic yards or 375 cubic feet of premixed concrete. Math’s calculation:- 1) square footage of slab = 30×30 = 900 sq ft, 2) 4″ thickness in inches = 5÷12 = 0.416 feet, 3) volume of slab in cubic feet = 900×0.416 = 375 cubic feet, and 4) volume of slab in cubic yards = 375÷27 = 14 cubic yards. Thus, you will need 14 cubic yards or 375 cubic feet of premixed concrete for a 30×30 slab at 5 inches thick.

**How many yards of concrete do I need for a 30×30 slab at 6″ thick**

At 6″ thick, for a 30×30 slab, generally, you will need 14 cubic yards or 375 cubic feet of premixed concrete. Math’s calculation:- 1) square footage of slab = 30×30 = 900 sq ft, 2) 4″ thickness in inches = 6÷12 = 0.5 feet, 3) volume of slab in cubic feet = 900×0.5 = 450 cubic feet, and 4) volume of slab in cubic yards = 450÷27 = 17 cubic yards. Thus, you will need 17 cubic yards or 450 cubic feet of premixed concrete for a 30×30 slab at 6 inches thick.

**Conclusions:-**

For a 30×30×4 slab, generally, you will need approximately 11 cubic yards or 297 cubic feet or either 660- 60lb or 495- 80lb bags of premixed concrete. At 5″ thick, 14 cubic yards or 375 cubic feet of concrete will be required and at 6″ thick, 17 cubic yards or 450 cubic feet of concrete will be necessary. Always you should purchase 5 to 10% more premixed than required.