A concrete bag is a ready-mix material that comprises cement, gravel, sand, and other ingredients. The number of concrete bags in one cubic foot depends on the size of the bag you choose. The number of concrete bags differs for all sizes, such as 40lb, 50lb, 60lb, etc.

So here, we will discuss the general calculation of concrete bags in one cubic foot according to the size. Also, we will estimate cubic feet in one 40lb, 50lb, etc., concrete bag, and vice versa.

**General Evaluation Method To Find Out Concrete Bags In A Cubic Foot**

There are around two different methods by which you can determine the number of concrete bags in one cubic foot. But before that please keep in mind that one cubic feet is equal to 133 lbs concrete. It is decided on its density that may vary according to the amount of gravel, sand, and aggregate. **(1 cubic foot = 133lbs concrete)**

**Method 1 – Using Weight/Size **

You can take any size of the concrete bag such as 40, 50, 60, 80, 90 lbs and find out the number of concrete bags accordingly. You have the data regarding the size of your bag in lbs and also that one cubic foot is about 133 lbs substantial. All you need to do is divide 133 lbs by the size (in lbs) of your concrete bag, and you will be getting the number of bags in a cubic foot.

**Concrete bags in one cubic foot = 133 lbs / Size Of Concrete bag (lbs)**

**Method 2 – Using Cubic Feet Of One Concrete Bag**

In this method, first, you have to evaluate the cubic feet covered in one bag of concrete according to its size. Later, you have to find the bags count for one cubic foot, then only divide 1 by the cubic feet you found in every bag size.

Hence,

**Concrete bag count = 1 cubic feet / cubic feet in concrete bag as per size (lbs)**

With both these methods, you will get the correct as well as the same result. It depends on you which method to use and which one seems easy to find quickly. Thus, let us check out how many bags of concrete (different sizes) are in a cubic foot –

**How Many 40lbs Concrete Bags Are In A Cubic Foot?**

Here, we will be trying both methods to get the result for a 40lbs concrete bag.

**Method 1 – **

According to the general formula discussed above,

Concrete bags in 1 cubic feet = 133/40 = 3.32 bags

**Method 2 – **

As per the above formula, we first have to find out cubic feet in a 40lbs concrete bag.

Cubic feet in 40lbs bag = 40/133 (as one cubic foot = 133 lbs and we know the size of the bag is 40 lbs)

Therefore, Cubic feet in a 40 lbs bag = 0.3007 cubic feet.

Now add this value in the formula of counting concrete bags,

Number of concrete bags = 1/0.3007 = 3.32 bags

Hence, there are 3.32 concrete bags of 40 lbs size in cubic feet.

**How Many 50lbs Concrete Bags Are In A Cubic Foot?**

Calculations are similar as 40lbs, so let us directly check the answer with both methods –

**Method 1 – ** Applying the formula,

Concrete bags in one cubic foot = 133/50 = 2.66 bags.

**Method 2 – ** Finding cubic feet in 50 lbs bag,

Cubic feet in 50 lbs bag = 50/133 = 0.375 cubic foot

Adding the found value in the final formula to count required bags,

Number of concrete bags needed in 50lbs size = 1/0.375 = 2.66 bags

Therefore, there are 2.66 concrete bags of 50 lbs size in one cubic foot.

**How Many 60lbs Concrete Bags Are In A Cubic Foot?**

If you want to find out the required number of 60 lbs concrete bags for one cubic foot, you can calculate it by any of the two methods discussed above –

**Method 1 – ** Apply Formula of concrete bags count as we have required data,

Count of 60 lbs Concrete Bags in a cubic feet = 133/60 = 2.21 concrete bags

**Method 2 – ** As per this method, we are not having the value of cubic feet in 60 lbs bag; let us find out –

Cubic feet in 60 lbs = 60/133 = 0.451 cubic foot.

Then,

Number Of 60 lbs Concrete bags Needed = 1/0.451 = 2.21 bags

So, you will observe that 2.21 concrete bags of 60 lbs size are there in one cubic foot.

**How Many 80 lbs Concrete Bags Needed In A Cubic Feet?**

Using two methods, let’s find out the number of 80 lbs concrete bags needed in one cubic foot –

**Method 1 – ** Add data in the formula for evaluation,

Number of 80lbs concrete bags needed in one cubic foot = 133/80 = 1.66 concrete bags.

**Method 2 – ** Calculate the cubic foot in 80 lbs concrete bag,

Cubic feet in 80 lbs concrete bag = 80/133 = 0.601 cubic feet

Adding this in the formula of counting bags,

Number of 80lbs concrete bags in a cubic foot = 1/0.601 = 1.66 concrete bags

Hence, there are 1.66 concrete bags of 80lbs in one cubic foot.

**How Many 90 lbs Concrete Bags Are In A Cubic Foot?**

Using two methods, you will find the result below-

**Method 1 – ** Calculate bags count directly by formula,

Number of 90 lbs concrete bags in a cubic foot = 133/90 = 1.47 bags

**Method 2 – ** Finding the cubic feet in 90 lbs is the first step,

Cubic feet in 90 lbs concrete bag = 90/133 = 0.676 cubic feet

Now, adding the values in the formula of counting bags is the last step,

Number of 90 lbs concrete bags in a cubic foot = 1/0.676 = 1.47 concrete bags

Therefore, there are 1.47 concrete bags of 90 lbs in a cubic foot.

In short, there are 3.32 concrete bags of 40 lbs, 2.66 bags of 50lbs, 2.21 bags of 60lbs, 1.66 concrete bags of 80 lbs, and 1.47 bags of 90 lbs in a cubic foot.