How many concrete bags do I need for 4×4 and 4×8 size slabs? It totally depends upon the size of the concrete bags and the thickness of the slab. So we will discuss in this article how many concrete bags are required for 4×4, and 4×8 slabs if the thickness of the slab is 4, 4.5, 5, 5.5, or 6 inches.

Usually, the standard slab thickness is 4 inches, and if anywhere slab thickness is not provided, then you should consider 4 inches as slab thickness.

## How many concrete bags do I need for 4’×4′, and 4’×8′ slab

The standard slab thickness is 4 inches but in this article, we will calculate concrete bags for the slab by taking different thicknesses.

### How many concrete bags do I need for a 4×4 slab?

To calculate the required number of concrete bags for a 4×4 slab. We have to know the size of the concrete bags and the thickness of the slab. But as I already told you if slab thickness is not provided, Then we should assume slab thickness as standard thickness. And standard thickness of the slab are 4 inches.

**Step to calculate the number of concrete bags for the slab**

- First of all, we have to find out the volume of the slab.
- After that, we have to find out the volume of the concrete bag.
- Then divide the slab volume by the concrete bag volume.

Then, you will get the required number of concrete bags for 4×4 slab.

let’s understand it by the example.

### How many concrete bags do I need for 4×4 4 inch thick slab

Here we have slab length = 4 feet

Slab width = 4 feet

Slab thickness = 4 inches convert it into feet = 4/12 = 0.33 feet.

According to my previous calculation, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 4 × 0.33

= 5.28 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 5.28 cubic feet = 5.28 × 45/27

= 5.28 × 1.66

= 8.76 = 9 bags.

So, 9 concrete bags of 80 pounds are required for 4×4 4-inch thick slab.

### How many concrete bags do I need for 4×4 4.5 inches thick slab

Here we have slab length = 4 feet

Slab width = 4 feet

Slab thickness = 4.5 inches convert it into feet = 4.5/12 = 0.375 feet.

According to my previous calculation, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 4 × 0.375

= 6 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 6 cubic feet = 6 × 45/27

= 6 × 1.66

= 9.96 = 10 bags.

So, 10 concrete bags of 80 pounds are required for 4×4 4.5 inches thick slab.

### How many concrete bags do I need for 4×4 5 inches thick slab

Here we have slab length = 4 feet

Slab width = 4 feet

Slab thickness = 5 inches convert it into feet = 5/12 = 0.416 feet.

According to my previous calculation, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 4 × 0.416

= 6.666 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 6.666 cubic feet = 6.666 × 45/27

= 6.666 × 1.66

= 11 bags.

So, 11 concrete bags of 80 pounds are required for 4×4 5-inch thick slab.

### How many concrete bags do I need for 4×4 5.5 inch thick slab

Here we have slab length = 4 feet

Slab width = 4 feet

Slab thickness = 5.5 inches convert it into feet = 5.5/12 = 0.458 feet.

According to the thumb rule, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 4 × 0.458

= 7.382 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 7.382 cubic feet = 7.382 × 45/27

= 7.382 × 1.66

= 12.16 = 12 bags.

So, 12 concrete bags of 80 pounds are required for 4×4 5.5 inches thick slab.

### How many concrete bags do I need for 4×4 6 inches thick slab

Here we have slab length = 4 feet

Slab width = 4 feet

Slab thickness = 6 inches convert it into feet = 6/12 = 0.5 feet.

According to the thumb rule, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 4 × 0.5

= 8 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 8 cubic feet = 8 × 45/27

= 8 × 1.66

= 13.28 = 13 bags.

So, 13 concrete bags of 80 pounds are required for 4×4 6-inch thick slab.

### How many concrete bags do I need for a 4’×8′ slab?

To calculate the required number of concrete bags for a 4×8 slab. We have to know the size of the concrete bags and the thickness of the slab. But as I already told you if slab thickness is not provided, Then we should assume slab thickness as standard thickness. And standard thickness of the slab is 4 inches.

**Step to calculate the number of concrete bags for the slab**

- First of all, we have to find out the density of the slab.
- After that, we have to find out the concrete bags’ density.
- Then divide the slab density by the concrete bag density.

Then, you will get the required number of concrete bags for 4×8 slab.

let’s understand it by the example.

### How many concrete bags do I need for 4×8 4 inches thick slab

Here we have slab length = 4 feet

Slab width = 8 feet

Slab thickness = 4 inches convert it into feet = 4/12 = 0.33 feet.

**concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 8 × 0.33

= 10.56 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 5.28 cubic feet = 10.56 × 45/27

= 10.56 × 1.66

= 17.529 = 17.5 bags.

So, 17.5 concrete bags of 80 pounds are required for 4×8 4-inch thick slab.

### How many concrete bags do I need for 4×8 4.5 inches thick slab

Here we have slab length = 4 feet

Slab width = 8 feet

Slab thickness = 4.5 inches convert it into feet = 4.5/12 = 0.375 feet.

According to the thumb rule, 45 bags of 80 lbs of **concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 8 × 0.375

= 12 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 6 cubic feet = 12 × 45/27

= 12 × 1.66

= 19.92 = 20 bags.

So, 20 concrete bags of 80 pounds are required for a 4’×8′ 4.5 inches thick slab.

### How many concrete bags do I need for 4’×8′ 5 inch thick slab

Here we have slab length = 4 feet

Slab width = 8 feet

Slab thickness = 5 inches convert it into feet = 5/12 = 0.416 feet.

**concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 8 × 0.416

= 13.312 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 6.666 cubic feet = 13.312 × 45/27

= 13.312 × 1.66

= 22 bags.

So, 22 concrete bags of 80 pounds are required for 4×8 5-inch thick slab.

### How many concrete bags do I need for 4×8 5.5 inch thick slab

Here we have slab length = 4 feet

Slab width = 8 feet

Slab thickness = 5.5 inches convert it into feet = 5.5/12 = 0.458 feet.

**concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 8 × 0.458

= 14.656 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 7.382 cubic feet = 14.656 × 45/27

= 14.656 × 1.66

= 24.32 = 24 bags.

So, 24 concrete bags of 80 pounds are required for 4×8 5.5 inches thick slab.

### How many concrete bags do I need for 4×4 6 inches thick slab

Here we have slab length = 4 feet

Slab width = 8 feet

Slab thickness = 6 inches convert it into feet = 6/12 = 0.5 feet.

**concrete bags comes in a cubic yard**. And 1 cubic yard is equal to 27 cubic feet.

The density of the given slab = length × width × thickness

= 4 × 8 × 0.5

= 16 cubic feet.

Hence, In 27 cubic feet 45 concrete bags

therefore, 1 cubic foot = 45/27

So, 8 cubic feet = 16 × 45/27

= 16 × 1.66

= 25.56 = 25.5 bags.

So, 25.5 concrete bags of 80 pounds are required for 4×8 6-inch thick slab.

#### Conclusion

Guys in this article we have known **how many concrete bags do I need for 4×4 slab** and we have also learned **how to calculate how many concrete bags I need for 4’×4′ slab** and **how many concrete bags do I need for a 4’×8′ slab**. But according to the size of concrete bags and slab thickness, it can be different.