**Estimating Concrete Hollow Block Quantity**

Concrete Hollow Blocks are used for a variety of purposes and are classified as load-bearing and non-load bearing blocks. Local hardware stores usually have a variety of 3 commercially-available CHBs – 4”, 6”, 8”.

**HOW TO ESTIMATE THE QUANTITY OF CHB FOR YOUR CONCRETE WALL:**

The easiest way to estimate CHB quantity is by the Area Method. A piece of standard concrete hollow block (CHB) has a surface area of 0.08 m^{2}. In accordance to this, a one square meter area will require 12.5 pcs of CHB.

^{2}/ 0.08m

^{2}=

**12.5 pcs of CHB**

- Determine your initial wall area:
- Determine door and window areas:
- Get your total wall area:
- Multiply your total wall area by 12.5, the number of pieces needed for a 1m
^{2}wall:

Determine the area of your wall. The formula for a square wall is Length * Height.

**Square Wall Area = Length * Height**

Make sure to take into consideration the often overlooked information that will affect the area of your wall – for example, the depth of your beam or the underground foundation CHB.

Determine if there are any openings in your wall – e.g. windows or doors. If there are, get the total area of the openings.

Subtract your total openings with the initial area of your wall.

**Total Wall Area = Initial Wall Area – Total Wall Opening Area**

**No. of CHB = Total Wall Area * 12.5**

**SAMPLE PROBLEM 1**

Compute for the quantity of 4” concrete hollow blocks (CHB) needed for a wall that is 3 meters high and 2 meters long.

**SOLUTION**

- Determine your initial wall area:
- Determine door and window areas:
- Get your total wall area:
- 4. Divide your total wall area by 12.5, the number of pieces needed for a 1m
^{2}wall:

** Square Wall Area ** = Length * Height

= 2m * 3m

** = 6m ^{2} **

** There are no specified doors or windows. **

** Total Wall Area ** = Initial Wall Area – Total Wall Opening Area

= 6m^{2} – 0m^{2}

** = 6m ^{2} **

** No. of CHB ** = 6m^{2} * 12.5

** = 75 pcs. of CHB **

**SAMPLE PROBLEM 2**

Compute for the quantity of 8” concrete hollow blocks (CHB) needed for a wall that is 3 meters high and 5 meters long with a door that is 2.1 meter high and 0.6 meter wide and a window that is 0.6 meter wide and 1 meter high.

**SOLUTION**

- Determine your initial wall area:
- Determine door and window areas:
- Get your total wall area:
- Divide your total wall area by 12.5, the number of pieces needed for a 1m
^{2}wall:

** Square Wall Area ** = Length * Height

= 5m * 3m

** = 15m ^{2} **

** Door Area ** = 2.1m * 0.6m

** = 1.26m ^{2} **

**Window Area**= 1m * 0.6m

**= 0.6m**

^{2}**Total Opening Area**= 1.26m

^{2}+ 0.6m

^{2}

**= 1.86m**

^{2}

** Total Wall Area ** = Initial Wall Area – Total Wall Opening Area

= 15m^{2} – 1.86m^{2}

** = 13.14m ^{2} **

** No. of CHB ** = 13.14m^{2} * 12.5

= ** 164.25 pcs of CHB
~ 165 pcs. of CHB **

Is this article useful? Let us know by following us on Facebook and sharing this article with the hashtag #veriaconcyclopedia

**Suggested Articles:**

"The Lord makes firm the steps of the one who delights in him;

though he may stumble, he will not fall, for the Lord upholds him with his hand."

Psalm 37:23-24 (NIV)