How Many Bags of Concrete Do I Need

How Many Bags of Concrete Do I Need?

Bags of concrete is required according to the requirement of the concrete. Bags of concrete depends on the size of the structure, if the concrete requirement is more then we need more bags of concrete and if the concrete requirement is less then we need less amount of concrete bags.

In the example of for 10’ x 10’ x 5” slab is below

Method – 1 

• The weight of concrete= [(10 x 10 x (5)/12] x 133.34 = 5556 pound= 2520 kg
• If the weight of concrete is 40 kg, the number of bags required= (2520/40) = 63 nos.
• If the weight of concrete is 40 lb, the number of bags required= (2520/18.14) = 140 nos. (1 lb = 0.45 kg)

Method – 2

Step-1: Calculate Volume of Concrete Required Pouring 10 X 10 Slab Thickness  4 inch

The calculation of volume of slab is the multiplying of length, width and thickness.

Example:

Let’s consider 10′ x 10′ slab with thickness 4”

• Length= 10 feet
• Width= 10 feet
• Thickness= 4”
• Volume of concrete= L x B x T
• Volume of concrete = 10 x 10 x (0.33)
• Volume of concrete = 33.00 cu. Ft……….(Because 12” = 1 feet, 4/12 = 0.33 feet)
• It is equal to 0.23 cu. Meter or 0.3 cubic yard.

Explanation:

• 3 ft= 1 yard, 3ft x 3 ft x 3ft = 1 yard x 1 yard x 1 yard
• 27 cubic feet = 1 cubic yard
• After that, we divide 33 cubic feet by 27 to get the volume of concrete in the cubic yard.
• Volume of concrete = 33/27 = 1.22 cubic yard

Step-2: Adding 10% of Extra Volume

• Now we are adding 10% of extra volume because of dry volume and wastage of concrete.
• 1.23 x 10% = 1.23 x (10/100) = 0.122 cubic yard
• So, the total volume of concrete = Original Volume + Extra Volume = 1.23 + 0.122 = 1.35 cubic yard

Step-3: Find Out How Many Bags of Concrete Do I Need

• To find the bags required to pour the slab, we need to divide the volume of concrete by yield of concrete bags.
• Bags are generally available in different sizes like 40lb, 45lb, 60lb, 80lb, and 90lb.

Different bag sizes and their yield values are given in the chart-

• From the upper table, we are using a 40 lb bag and the yield value is 0.011 cubic yards.
• So, number of bags are calculated by dividing total volume of concrete with yield vale of bags.
• So, 1.35/0.011 = 122 bags
• So, for 10 x 10 slab with a thickness of 4”, we need 122 bags of concrete.

Also, read: What Is Unit Weight | What Is Density | What Is Unit Weight Material | Unit Weight Building Materials

Different Brands of Dry Mix Concrete Bags

Different brands of dry mix concrete bags are-

• Ultra Tech Cement
• ACC Limited
• Nuvoco
• RDC Concrete
• Build Supply
• Shaila

Also, read: What Is Plumbing | Systems of Plumbing | Difference Between One pipe, Two Pipe, Single Stack, and Single Stack Partially Ventilated | How to Choose of Plumbing System.

How Many Bags of Concrete Do I Need for Slab with 4” Thickness?

Method – 1 

• The weight of dry concrete is 3600 pounds per cubic yard.
• So, the weight of dry concrete per cubic foot = 3600/ = 133.34 pounds
• [as we know, 1 yard = 3 feet]

Let’s Assume,

• Length of slab = 5 feet
• Width of slab = 5 feet
• S0, the weight of dry concrete = [{Length (in foot) x Width (in foot) x Thickness (in inches) / 12} x 133.34] = Weight (in pounds)

In this Case,

• [(5 x 5 x 4) / 12] x 133.34 = 1111.16 pounds = 504 kg
• The weight of one of dry cement concrete is 40 kg
• So, the number of bags are required = 504/40 = 12.6 nos.

Method – 2

Step-1: Calculate Volume of Concrete Required Pouring 5 X 5 Slab Thickness 4 inch

The calculation of volume of slab is the multiplying of length, width, and thickness.

Example: 

Let’s consider 5×5 slab with thickness 4”

• Length= 5 feet
• Width= 5 feet
• Thickness= 4”
• Volume of concrete= L x B x T
• Volume of concrete = 5 x 5 x (0.33)
• Volume of concrete = 8.25 cu. Ft. …………(Because 12” = 1 feet, 4/12 = 0.33 feet)
• It is equal to 0.23 cu. Meter or 0.3 cubic yard.

Explanation:

• 3 ft= 1 yard, 3ft x 3 ft x 3ft = 1 yard x 1 yard x 1 yard
• 27 cubic feet = 1 cubic yard
• After that we divide 8.25 cubic feet by 27 to get the volume of concrete in cubic yard.
• Volume of concrete = 8.25/27 = 0.3 cubic yard

Step-2: Adding 10% of Extra Volume

• Now we are adding 10% of extra volume because of dry volume and wastage of concrete.
• 0.3 x 10% = 0.3 x (10/100) = 0.03 cubic yard
• So, the total volume of concrete = Original volume + Extra volume = 0.3 + 0.03 = 0.33 cubic yard

Step-3: Find Out How Many Bags of Concrete Do I Need

• To find the bags required to pour the slab, we need to divide the volume of concrete by yield of concrete bags.
• Bags are generally available in different sizes like 40lb, 45lb, 60lb, 80lb and 90lb.

Different bag sizes and their yield values are given in the chart-

• From the upper table, we are using 40 lb bag and the yield value is 0.011 cubic yard.
• So, number of bags are calculated by dividing total volume of concrete with yield vale of bags.
• So, 0.33/0.011 = 30 bags
• So, for 5 x 5 slab with a thickness of 4”, we need 30 bags of concrete.

How Many Bags of Concrete Do I Need for Slab with 5” Thickness?

Method – 1 

Let’s assume,

• Length of slab = 5 feet
• Width of slab = 5 feet
• Previously we determined that the weight of dry concrete per cubic foot is 133.34 pounds.
• S0, the weight of dry concrete = [{Length (in foot) x Width (in foot) x Thickness (in inches) / 12} x 133.34] = Weight (in pounds)

In this case,

• [(5 x 5 x 5) / 12] x 133.34 = 1389 pound = 630 kg
• The weight of one of dry cement concrete is 40 kg
• So, the number of bags are required = 630/40 = 16 nos.

Method – 2

Step-1: Calculate Volume of Concrete Required Pouring 5 X 5 Slab Thickness 5 inch

The calculation of volume of slab is the multiplying of length, width and thickness.

Example:

• Let’s consider 5×5 slab with thickness 5”
• Length= 5 feet
• Width= 5 feet
• Thickness= 5”
• Volume of concrete= L x B x T
• Volume of concrete = 5 x 5 x (0.42)
• Volume of concrete = 10.5 cu. Ft………..(Because 12” = 1 feet, 5/12 = 0.42 feet)
• It is equal to 0.39 cubic yard.

Explanation:

• 3 ft= 1 yard, 3ft x 3 ft x 3ft = 1 yard x 1 yard x 1 yard
• 27 cubic feet = 1 cubic yard
• After that we divide 10.5 cubic feet by 27 to get the volume of concrete in cubic yard.
• Volume of concrete = 10.5/27 = 0.39 cubic yard

Step-2: Adding 10% of Extra Colume

• Now we are adding 10% of extra volume because of dry volume and wastage of concrete.
• 0.39 x 10% = 0.39 x (10/100) = 0.04 cubic yard
• So, the total volume of concrete = Original volume + Extra volume = 0.3 + 0.04 = 0.34 cubic yard

Step-3: Find Out How Many Bags of Concrete Do I Need

• To find the bags required to pour the slab, we need to divide the volume of concrete by yield of concrete bags.
• Bags are generally available in different sizes like 40lb, 45lb, 60lb, 80lb, and 90lb.

Different bag sizes and their yield values are given in the chart-

• From the upper table, we are using 40 lb bag and the yield value is 0.011 cubic yard.
• So, a number of bags are calculated by dividing total volume of concrete with yield vale of bags.
• So, 0.34/0.011 = 30.9 bags = 31 bags
• So, for 5 x 5 slab with a thickness of 5”, we need 31 bags of concrete.

Also, read: What Is Self Compact Concrete | What Is J-ring Test | Equipment of J-ring Test | Procedure of the J-Ring Test

How Many Bags of Concrete Do I Need for Slab with 6” Thickness?

Method – 1 

Let’s assume,

• Length of slab = 5 feet
• Width of slab = 5 feet
• Previously we determined that the weight of dry concrete per cubic foot is 133.34 pounds.
• S0, the weight of dry concrete = [{Length (in foot) x Width (in foot) x Thickness (in inches) / 12} x 133.34] = Weight (in pounds)

In this case,

• [(5 x 5 x 6) / 12] x 133.34 = 1666.75 pounds = 756 kg
• The weight of one of dry cement concrete is 40 kg
• So, the number of bags are required = 756/40 = 19 nos.

Method – 2

Step-1: Calculate Volume of Concrete Required Pouring 5 X 5 Slab Thickness 6 inch

The calculation of volume of slab is the multiplying of length, width and thickness.

Example: 

• Let’s consider 5 x 5 slab with thickness 6”
• Length= 5 feet
• Width= 5 feet
• Thickness= 6”
• Volume of concrete= L x B x T
• Volume of concrete = 5 x 5 x (0.5)
• Volume of concrete = 12.5 cu. Ft…………(Because 12” = 1 feet, 6/12 = 0.5 feet)
• It is equal to 0.46 cubic yard.

Explanation:

• 3 ft= 1 yard, 3ft x 3 ft x 3ft = 1 yard x 1 yard x 1 yard
• 27 cubic feet = 1 cubic yard
• After that, we divide 12.5 cubic feet by 27 to get the volume of concrete in cubic yard.
• Volume of concrete = 12.5/27 = 0.46 cubic yard

Step-2: Adding 10% of Extra Volume

• Now we are adding 10% of extra volume because of dry volume and wastage of concrete.
• 0.46 x 10% = 0.46 x (10/100) = 0.05 cubic yard
• So, the total volume of concrete = Original volume + Extra volume = 0.3 + 0.05 = 0.35 cubic yard

Step-3: Find Out How Many Bags of Concrete Do I Need

• To find the bags required to pour the slab, we need to divide the volume of concrete by yield of concrete bags.
• Bags are generally available in different sizes like 40lb, 45lb, 60lb, 80lb, and 90lb.

Different bag sizes and their yield values are given in the chart-

• From the upper table, we are using 40 lb bag and the yield value is 0.011 cubic yard.
• So, a number of bags are calculated by dividing total volume of concrete with yield vale of bags.
• So, 0.35/0.011 = 31.8 bags = 32 bags
• So, for 5  x 5 slabs with a thickness of 6”, we need 32 bags of concrete.

How Many Bags of Concrete Do I Need for Slab with 8” Thickness?

Method – 1 

Let’s assume,

• length of slab = 5 feet
• width of slab = 5 feet
• Previously we determined that the weight of dry concrete per cubic foot is 133.34 pounds.
• S0, the weight of dry concrete = [{Length (in foot) x Width (in foot) x Thickness (in inches) / 12} x 133.34] = Weight (in pounds)

In this case,

• [(5 x 5 x 8) / 12] x 133.34 = 2223 pound = 1008.34 kg
• The weight of one of dry cement concrete is 40 kg
• So, the number of bags are required = 1008.34/40 = 25 nos.

Method – 2

Step-1: Calculate Volume of Concrete Required Pouring 5 X 5 Slab Thickness 7 inch

The calculation of volume of slab is the multiplying of length, width and thickness.

Example:

• Let’s consider 5×5 slab with thickness 8”
• Length= 5 feet
• Width= 5 feet
• Thickness= 8”
• Volume of concrete= L x B x T
• Volume of concrete = 5 x 5 x (0.67)
• Volume of concrete = 16.75 cu. Ft…………… (Because 12” = 1 feet, 8/12 = 0.67 feet)
• It is equal to 0.62 cubic yard.
• Explanation:
• 3 ft= 1 yard, 3ft x 3 ft x 3ft = 1 yard x 1 yard x 1 yard
• 27 cubic feet = 1 cubic yard
• After that we divide 16.75 cubic feet by 27 to get the volume of concrete in cubic yard.
• Volume of concrete = 16.75/27 = 0.62 cubic yard

Step-2: Adding 10% of Extra Volume

• Now we are adding 10% of extra volume because of dry volume and wastage of concrete.
• 0.62 x 10% = 0.62 x (10/100) = 0.062 cubic yard
• So, the total volume of concrete = Original volume + Extra volume = 0.3 + 0.062 = 0.362 cubic yard

Step-3: Find Out How Many Bags of Concrete Do I Need

• To find the bags required to pour the slab, we need to divide the volume of concrete by yield of concrete bags.
• Bags are generally available in different sizes like 40lb, 45lb, 60lb, 80lb, and 90lb.

Different bag sizes and their yield values are given in the chart-

• From the upper table, we are using a 40 lb bag and the yield value is 0.011 cubic yards.
• So, a number of bags are calculated by dividing total volume of concrete with yield vale of bags.
• So, 0.362/0.011 = 32.9 bags = 33 bags
• So, for 5  x 5 slab with a thickness of 8”, we need 33 bags of concrete.

Also, read: What Is Self Compact Concrete | What Is Slump Flow Test | Equipment for Slump Flow Test | Procedure of Slump Flow Test

How Many Bags of Quikrete Do I Need?

There are different numbers of bags are required a certain square feet design. The number of bags depends on the weight of those bags.

So, first, let’s assume the dimension of the required area is (5 x 5)= 25 square feet.

Quikrete bags required for-

Different weights for a 5 ‘x 5’ x 4 “slab size in a hair bag are as follows.

Different weights for a 5 ‘x 5’ x 5″slab size in a hair bag are as follows.

Different weights for a 5 ‘x 5’ x 6″slab size in a hair bag are as follows.

Different weights for a 5 ‘x 5’ x 8″slab size in a hair bag are as follows.

Also, read: What Is Self Compact Concrete | What Is Slump Flow Test | Equipment for Slump Flow Test | Procedure of Slump Flow Test

How Much Concrete Do I Need?

• According to the requirements of concrete, the bags will be decided.
• If the structure is large then it requires more bags of concrete and if the structure is small compared to the large structure then it required less number of bags.
• The example of how many bags of concrete do I need for a 10’ x 10’ x 5” slab is below-
• The weight of concrete= [(10 x 10 x 5)/12] x 133.34 = 5556 pound
• We know the density of dry mix concrete is 133 lb
• So, the volume is (5556/133)  = 41.78  = 1.18
• So, we need to order 1.18  dry concrete.