How to calculate number of blocks for your building project in 2 simple steps.

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.

Area=Length x Breadth, In this case since we are dealing with height,

Area=Length x Height

Calculate Length: Looking at figure 1,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














Ground Floor Plan




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.






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  1. Great explanation, thank you very much. This is so useful

  2. Just what I needed. Thank you so much!

  3. Osaromuta Jacob

    Please Mr nigerhouseplans,is there no need to add up the thickness of shocking mortar.

    • nighouseplans

      Dear Jacob, the mortar allowance typically cancels the extra blocks added for breakages or offcuts. So you can ignore it during an estimate. Regards.


    Thank you so much, I really learned

  5. Emma Anku

    Thanks. Kindly alaborate on the details of wall 9

  6. Onivald House Plans

    thanks a lot you really know how to explain keep doing great work

  7. Samuel Enuoyibo

    I really enjoyed your assistance

  8. Iduh Alex

    Please sir I was ask to,
    Calculate the total numbers of blocks required for a 1 bedroom and draw a plan

  9. Iduh Alex

    Calculate the total numbers of blocks required for a 1 bedroom and draw a plan

  10. Bala Babangida

    Thanks you sir I have learned a lot pls do you have any links to follow you.

    • nighouseplans

      You’re welcome Bala. You can subscribe to follow us.

  11. Innocent udoh

    Comment, pls o was asked to give the total number of blocks that can build 5 stores shop ,lenght 12 ,breath 10 from dpc to finishig. pls o need your help .thanks

    • nighouseplans

      Dear Innocent, Please see below:
      It’s not clear if the units is in meters of ft. Also is the 10 and 12 total length of per shop.

      Calculate the total perimeter of the building multiply by 2. Then multiply by the total number of courses. Foundation to DPC can be 4 courses while DPC to roof can be 13 courses… This is a total of 17 courses.


      If we assume you mentioned 10ftx12ft per shop.
      This is 3×3.6m per shop. Hence for 5 shops we have 15mx3.6m.

      To estimate blocks we calculate one course:
      15×3.6×2=108 blocks

      For all courses including foundation (17 courses)
      We do:

      108×17= 1836 blocks (estimated)

      Note: This is a quick and fairly accurate method. A more detailed method is outlined in the post.

  12. Udochukwu

    Thank you very much you assisted me in doing my assignment

  13. Sunday

    Thank so much very interested

  14. Smith Mulango

    Please i will like to know how wall 9 wall calculated to be 5600?

    • nighouseplans

      Dear Smith, we don’t quite understand what you mean.

      • 1,980 blocks for foundation or to the window level cos I dont understand

        • nighouseplans

          Dear Troy, this is for everything… The entire building including foundation.

    • Adebayo Sodiq Abdulrasheed

      Thank you very much, with this I can now plan for my building project

  15. Olanipekun Kehinde Hassan

    Please I want to calculate 5 bedroom Duplex

    • nighouseplans

      Dear Hassan, Kindly use the method highlighted or you can send the perimeter of the building and we can give you a rough idea of the number of blocks you need.

  16. Malachy Iroro Emeje

    Good morning. Pls in clear terms, how do calculate for the estimate of works for a storey block of 4flats( components of 2no. 3- bedroom flat and 2no. 2- bedroom flat respectively.

    • nighouseplans

      Good morning, in summary calculate the total area of block work and divide by the area of one block (.45mx.224m)

      Or calculate the length of one course of block work, multiply by the number of courses then subtract the number of blocks for doors and windows.

  17. Ngum Godlove tandah

    Thanks verymuch, i need more help in house calculation ,tiles, n sand,cement

    • nighouseplans

      Dear Ngum,for floor tiles, simply calculate total wall or floor area by multiplying the length and the breadth.sand and cement depends on the mix and will be attended to in a later post.

  18. Oziomz

    Thank you so much

  19. What if I want to know the number of blocks for the first course during the foundation

    • nighouseplans

      Dear Eben, in this case calculate the perimeter and length of walls inside and divide by . 45m which is the length of one block

  20. Badmus Saka

    Quite explanatory.
    Thanks so much

  21. nigerhouseplans,

    Thanks for the article, I like the flow and detailed explanation. This will be helpful not just to those in the building industry but to clients as well.

    Keep up the good work!

  22. Opalana Julius

    This is a good one

  23. Bright Owenvbiugie

    Thank you so much boss this is well understood


    I really appreciate your explanations. You are bless

  25. Arc Kolade Sulaiman

    That was a lovely detail explanation. At least it will really help in giving a client the back up to the number of blocks used on the site.

  26. Okike Earnest

    I really learnt alot. Thanks sir.
    Can you give explanation on how to calculate roofing sheet

    • nigerhouseplans

      Thanks for the compliment Okike, we may do this on a later post.

  27. Iseoluwa

    I love this explanation

  28. John Chukwuebuka Okeke

    Thanks a lot
    Great Builders

  29. Azubuike ibe Christopher

    I have a more easier step.
    Total length of wall = 59.105m
    Length of a block = 0.45m
    Total of blocks for each course: 59.1050.45 = 131blocks approximately
    Height of the wall 3m height of a block = 13.3courses + 4courses substructure = 17.3courses from fdn to roof level
    Therefore, total number of blocks required =
    Total number of blocks for each course multiply by the total number of courses.
    i.e 131*17.3 = 2267blocks minus the blocks in the openings

    Openings as calculated = 30.150m
    Area of a block = 0.45*.225 = 0.10125m
    Total blocks in the openings 30.1500.10125 = 298blocks

    i.e 2267 — 298 = 1969blocks very close with just difference of 1980 — 1969 = 11blocks

    • nigerhouseplans

      Thanks Mr.Christopher.


      Good afternoon sir, plz. I’ll need a 3 and 6 bedroom duplex plan that includes the calculations for the number of blocks, cement, rods, roofing materials, labor and other things that it’ll take to get the actual amount or close to it for its starting to finish.
      Tnx in advance for your anticipated favorable responses.

      • nigerhouseplans

        Dear Duncan, this is a bill of quantities or material list. We can advise on a rough estimate prior to purchasing a plan but the BoQ may be done after plan purchase if required. Thanks.

  30. Waxco Consult & Developers

    Wow! Thanks so much for this information, it’s indeed a refresher, Bigups Nigerplans

  31. Lovly very very good

  32. Israel

    Whoa. This was very helpful. Thanks so much

  33. Azeezat

    Thanks the article is really healful

  34. Thanks for sharing good information, how to produce concrete blocks with block making machine.

  35. Kayode Adeniyi

    I really appreciate for the simple enlighten on buildings project.I am builder.

  36. Ebenezer

    Very helpful ….thanks

  37. Emmanuel Gabriel

    These process review the details knowledge on how to calculate the amount of block in a giving project.thanks

  38. Henry moses

    Senior mens to study building is not an easy thing; but we thank God for giving us understanding always, pls if u dont know something ask and it shall be giving unto u

  39. Abdulsalam Abideen

    Pls what if we are to calculate the amount of blocks to be used for a wall
    Maybe for 1 8000mm

  40. daniel mark

    Thanks guys this article was really helpful

    • nigerhouseplans

      Dear Mr.Daniel, Thanks for the compliment. Regards.

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