See How To Calculate Number Of Blocks For Your Building Project
What is the number of blocks required to complete this building?
This is a common question asked by prospective home owners
especially after the building design phase.It is advised you use
trusted professionals for your building project. This saves you
time and money. However, if you are taking charge of material
procurement or just wish to confirm number of blocks required for
your project, these 2 simple steps outline the process outlines the
steps you need to take. A simple 1 bedroom apartment is used in
this case for clarity. These are the two basic steps: Step 1:
Calculate wall areas. Step 2: Divide total wall area by area of one
block. Step 1: To calculate wall areas, we will calculate the total
length of walls and multiply by wall height(see plan image below).
Area=Length x Breadth, In this case since we are dealing with
height, Area=Length x Height Calculate Length: Looking at figure
1 below,we take length of vertical walls first(from left to right),
then horizontal walls(from top to bottom) Wall 1= 8000mm ,
Wall2=7755mm, Wall 3=3675mm, Wall 4=4100mm, Wall
5=3900mm, Wall 6=7950mm Wall 7=3525mm, Wall 8=5975mm,
Wall 9=5600mm, Wall 10=4425mm, Wall 11=4200mm Sum of all
wall length is=59,105mm. Use height of wall at 3000mm. Rough
wall area (Wall area including openings) =59105mmx3000mm=
177,315,000mm Remember we have some wall openings at the
entrance, doors and windows. We have to subtract areas for these
to get the actual wall area: We have 6 doors with measuring
900mmx2100mm: 6x900mmx2100mm= 11,340,000mm*2 We have
8 windows measuring 1200mmx1200mm: 8x1200mmx1200mm=
11,520,000mm2 We have 1 window measuring 600mmx600mm:
1x600mmx600mm= 360,000mm2 We have 1 opening measuring
3300mmx2100mm: 1x3300mmx2100mm= 6,930,000mm2 Add up
all opening areas: Opening area:
(11,340,000+11,520,000+360,000+6,930,000) mm2=
30,150,000mm2 Subtract opening area from the rough wall area:
Actual ground floor wall area: (177,315,000-30,150,000) mm2=
147,165,000mm2 Area of foundation walls: Also,remember we
have a foundation. The foundation area depends on the number of
courses laid. For this building, we use four courses of block wall
as foundation (Strip foundation). This is roughly 900mm high. We
simply multiply the perimeter of walls we got in step 1 by the
height of the foundation wall. Area is still length x height. But now
the height is 900mm. Area of foundation wall:
59105mmx900mm=53,194,500mm2 Total wall area = Ground floor
wall area+Foundation wall area =147,165,000mm2+53,194,500
mm2= 200,359,500 mm2 Step 2: Area of one block is
225mmx450mm= 101,250mm2 Number of blocks is total wall area
divided by area of one block: Hence, number of blocks
is:200,359,500/101,250= 1978.86 blocks That’s
approximately1,980 blocks. You may want to add a certain
percentage for breakages and off-cuts. If you use good quality
vibrated blocks you only need to add a little. Wish you success on
your building project.


  1. This is a nice writeup

  2. That’s good

  3. Good

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