How to calculate numbers of blocks from a building plan.

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Most asked question from a would be house owner is always how many blocks do I need to get my building completed. Hence this topic is written with illustrations to make it easy for you to do

the calculations yourself from the plan your architect gave you.
The plan above is for a 2 bedroom bungallow, so we are going to start from the basics having in
mind these factors-
i)The lenght of a block is 0.45m or 450mm or 18″
ii)The width of thickness varies -150mm or 6″ and 225mm or 9″ which are most common.
ii)Taking for a general or average purpose, the blocks laid from foundation to dpc(german or
oversite concrete) is 4 coaches/levels. From dpc to the base of window another 4 coaches,from
base of window to top of window another 5 coaches, then from top of window to base of roof
another 3 coaches, neglecting the lintel or concrete on top of window.
Now with these parameters let calculate the plan above which has a wall of 150mm or 6″ all
Add the length and breadth of the blockwall for external and internal
Therefore (A)9,400mm +9,600mm(B)+9400(C)+9600(D)=38,000mm or 38m
Now add the internal walls too
(Follow the grid lines and check the corresponding dimensions on plan remember 150mm is the
block width)
(Grid 7)150+3600+150+150+3600+150=7,800mm or 7.8m
(Grid 6)1350+150+2250+150+825+675+150=5,550mm or 5.55m
(Grid 1b)800+2400+1300+900+100=5,500mm or 5.5m
(Grid 2)2600+900+100+150+100+900+500+150=5,400mm or 5.4m
(Grid 3)1800+150+650+900+250+900+1450=6,100mm or 6.1m
(Grid 3b-Kitchen)900+50+1200+50+150=2,350 or 2.35m
(Grid 7b toilet)1800 or 1.8m
Total internal walls=34,500mm or 34.5m
Therefore Total walls=38,000mm +34,500mm=72,500mm or 72.5m
Now for the first 4 coaches to dpc level the wall will run right through, i.e the spaces for
doors or windows are not left out (n/b- blocks are used in relatively strong and stable soil not
waterlogged area that requires concrete instead).
Divide the sum by 450mm to know the numbers needed for one level/layer/coach of blocks
72,500/450=161 blocks
From dpc level to roof lets take the numbers of coaches to be 4+5+3=12 coaches
then multiply the numbers of blocks for each coach above by 12
161 x 12=1932 blocks
Don’t forget we have windows and doors spaces which we need to remove,for each window of 1200mm
take numbers of the block to be 14 (i.e 1200/230=5.2 and 1200/450=2.6 ,5.3 x2.6=14 approx
Now count the numbers of 1200mm windows and multiply by 14
Total numbers of 1200mm windows as counted on plan is 12 (note 2400mm window was taken as two of
1200mm window)
i.e 11 x 14 =154 blocks + 7 blocks for 600mm window for toilet. Total=161 blocks
Now calculate for doors,Numbers of blocks for a door of 900mm is 18.
height of a door(2100/225=9)+width of a door (900mm/450mm=2). so 9 x2 =18 blocks for each door.
Multiply 18 by numbers of doors=18 x8=144 blocks
Add 144+161=305 blocks,then remove from total blocks of 644 (for dpc) + 1932
Total numbers of blocks reqd=2,271 blocks
For a quick calculation, having the entire length to be 72,500mm. Take for a bungallow total
lenght from foundation to roof to be 1,200mm +3000mm=4200mm
Then calculate the surface area which is 72,500 x 4200 and convert to meters
72.5m x 4.2m=304.5m2
Remove surface areas of windows and doors
For window, height is 1.2m and total is 11
i.e 1.2m x 1.2m x 11=15.84m2 +0.6 x0.6(toilet window)=16.2m2
For doors, height is 2.1m while width is 0.9m
i.e 0.9 x 2.1 x 8(nos of doors)=15.12
Total area for doors and windows=16.2m2 +15.12m2=31.32m2
Remove 31.32m2 from 304.5m2=273.18m2
Now divide this by surface area of a block which is 0.225 x 0.45=0.10125
The blocks reqd caculated by this method is 273.18m2/0.10125=2,698 blocks
Note a difference of about 400 blocks from the two calculations. Of course you can’t get exactly
the numbers you need but the first method is close to it. And calculations are not 100% true
because of these factors
1-The mortar space was not considered
2-Blocks that will be wasted due to breakages e.t.c

178 thoughts on “How to calculate numbers of blocks from a building plan.

    • This site is not to disenfranchise builders but is to encourage more Nigerians and Africa in general to build their own houses.

  1. Knowledge is power and information a weapon when in the hands of the wise. Having the quality of information you are supplying on your site will definitely keep us ahead of fraudulent building contractors. But I dare to say that supervision can also go a long way in ensuring getting the right kind and quality of building services we require.

  2. I prefer method 1 plus 10% to make up for differences and breakages. This would give us 2271*227=2498. Lets say 2500 blocks which is fair and much more realistic than method 2. I’ll write an excel prog to do this calculations for me for every plan. I will find a way to share when I do.

  3. Man, you are doing a wonderful job. I wonder if there is any nigerian that can do this without asking for money. God will continue to bless you.
    Please tell me, how many blocks can I use to put up a 4-bedroom flat.

  4. I appreciate what you have done and want to be informed well be the actual name of the levels of blocks laid i.e ‘coaches’ or courses? As a teacher I will assume all you said to be true and I do not see the interchanging of the above words to be okay for fear of misinformation. Keep up with the good work

  5. I appreciate what you have done and want to be informed well about the actual name of the levels of blocks laid i.e ‘coaches’ or courses? As a teacher I will assume all you said to be true and I do not see the interchanging of the above words to be okay for fear of misinformation. Keep up with the good work,

  6. I’m short of words, don’t know what to say to you, God Bless you for posting this but pls don’t remove anything from here as we engineers will always need it.

  7. hello guyz am Dan,a quantity surveyor in making.i must confess dis is brilliant its my job buh ur doin it so perfectly i learnt new tins 4rm u.kip it up.

  8. An ideal builder dose’nt cheat. Please know that we calculate for un-avoidable waste thanks. N.B. You did a nice job here

  9. my point is stop making it too simple,let it be more technical so that its the real professionals or construction students it wil appeal to and boring/confusing to those who don’t have any business there. Let them get the service of professional!

  10. Though, you’ve tried but want to remind building clients that they should avoid quack contractors, because they’ve no sound jobs to provide rather than waste products. For me I make sure I charge my various client what will due for my work expertise and render my best service to them. Honestly, all my client all over the globe love me and my artistic hand work. It is GOD’S doing. Cheers.

  11. Thanks man. But I think there is a little mistake in the first calculation that changed the result of second calculation. You added the dpc blocks twice. Because if the total girth is 72500mm/450=161blocks per coach, multiply by 12coaches=1932.then diduct the openings which is 305=1627blocks. Then add 5% waste.

  12. What a gr8 job well done, i am thrilled about this calculation, most esp. We in Building Technology, and also a Teacher of Brick, Blocklaying and concrete at GTC in Enugu, it has created a tremendious value to breake down my lession plan when it comes to calc. Of blocks, and i prefer mtd1. Kp d gud wrk.

  13. pls i need answer to this question,how block should be lay into foundation before your write up you put 4 coaches/levels but from my research i observe that 3 coaches of block is put into the foundation before dpc.pls any reaction to this

    • There is no standard on the numbers of block it depends on the design, topography or level of ground and what you can afford. You noticed this in your area because is highland.

  14. Thanks very much Emma, for what you have describe on how to calculate a number of blocks in a plan, most of time i use to ask my friend to do it for me but now i thank you i will start to calculate my self.
    keep it up
    i love it.

  15. Pls sir, i want u 2 explain 2 me how to convert metre cubic to tones. eg 3.8m3 to tones how ll i go abt it sir….

  16. Tankz 4 dis wonderfull work i am really impressd 2 see dat we hav compitent engineers like u. Keep up d civil engr. Flag flaying.

  17. Sir,I am in need of suitable plan drawing for a land of 30ft by 120ft such that the frontage or half of the land is needed to be used for a four bedroom flat while the remaining half is needed for mini flat of room and parlour,kitchen toilet and bath en suite.And the cost for the accomplishment of the project.

  18. Weldone a very good submission you have and highly educating , the only observation though is the layer of block is “course” and not “coach” as you kept repeating believe it must be a typo .

  19. You save a society if not a world for this highlights. More than a job well done. Thank you so much man.

  20. Its good for every 1 to learn d basics, howeva, I must caution here dat drwns r not always tis simple and a Civil Engr. must be consulted when d need arises.

  21. Hi Emma,
    I av bn receiving ur e-mails, thanks so much. I av a worry that your site posts are too simple, please be more tecnical, you are rather strenghtening the arm of quacks. There are professionals in the field, thanks.

  22. I must commend u, u did a nice job and calculations here, but u did not deduct the Lintels(concrete work) because they are not block work. If u do thatu will get the acurate number of blocks required. Thanks

  23. I really appreciate your calculations and don’t even bordered to pay attention to some people’s crazy comment you did this because you wanted many people success in life only GOD can pay you back all your effort of generocity,may GOD bless you,your family and your unborne generations thank you sooooo much.

  24. Thanks. An easier way is just to keep in mind that ‘for every 10 feet, 6 blocks are required. Hence cal the total length of the wall, multiply by 6 and divide by 10. Example for the length of 72500mm equals to 238feet. Now no of bloks =237*6/10 =143(each coache) now for 16 coache =143*16=2288. This has taken kia of d space for mortar. Just subtract the no of bloks for doors and windows. Hope this will be helpful

  25. If we have 1/10 of you kind of person then this world will be a better place, you are really “EMMANUEL”. May GOD bless you.

  26. My dear, I appreciate your good wood. Your information is helping lay men to have rudimentary knowledge about building so that they will not be cheated out completely. God bless you mightily.

  27. I pray God 4 his gr8t wisdom on u. Pls forward dis page 2 my e-mail box. Tnks

  28. your enlightment on this simple small building plan would definately encouraged sincere and honest building contractors.

  29. U’v done a gud job of educating wat is dpc and oversite concrete,how can one achieve d foundations 2 oversite concrete,is hard core important.

  30. I must confess you are my God sent, have been battled with this for a year. This is a good are the first person to give analysis or details of what have been willing to know thanKs so much you are the best by God grace.

  31. This gives me great encouragement to build. Never mind Nigerians who are overwhelmed by the cheating culture will not like this but keep it up. God will amazingly reward you and many genuine people will come paying you for this services you give out free. Imagine how many building students appreciate this. Keep it up.

  32. What a good job you have done here, but please let me know how many blocks will be needed for a 3-bedroom flat

  33. I wld want 2knw if u entertain calls c0s I’ve sent a number 0f unreplied messages 2u b0rdering 0n hw I culd be abs0rb in ur firm as an Intern 0r link 2 an0ther pr0fessi0nal, still an Undergraduate 0f Building wt d zeal 0f acquiring kn0wledge!

  34. Oh, at last a complete solution,am very greatful for your wisdom,little but mighty,thanks and God bless. Bravo…..

  35. you’ve done an excellent work my man,you don’t know how much you’ve helped me out. i’ll like to subscribe to your page or website if there is any for more info. thank you my man

  36. Wow, this is brilliant. One could self build. Have considered putting together a “fool’s” guide to self build, of course one would have professionals to certify each stage of the construction.
    Thank you mate, if anything at all this gives one some idea of costs and would help improve relation with builders / contractors.

  37. This is a brilliant work you have done here and d fact dt it’s free makes you an hero.
    I was so eager to know how many blocks and bags of cement I’ll need for this little project of mine so as to budget d little fund I ve for dis project and to maximize it. I was propelled to google so ur site appeared on d results and it’s really helpful.
    I followed d history of this post and realized dt it was posted in 2010 and still receives comments and readership till dis moment. Holy God can reward u for dis. I can’t wait to ve d e-mail in my inbox.

  38. Wow! You have just done my engineering a whole lot of good. God bless you. Am bookmarking your blog right away, then I’ll preach your gospel to my young engineering friends/colleagues.

  39. With all sincerity and appreciation, you have done a remarkable job. I just goggle this question, not knowing a valuable resource like this from a Nigerian will be available on the web. One does not need rocket science to understand every bit of what you have itemized here. It has given any serious minded fellow an estimate of what it takes to have a house. More grease to your efforts. For those complaining about professionalism, the author of the article has rightly pointed out that this piece is not a substitute for professional jobs. It serves a mere purpose of guiding prospective house owners. Once again, many thanks.

  40. this was nice of you .the 1st method was very clear and understanding and thats the method i kno . thanks and God bless

  41. Well its was a nice job, but please try and make it more complicating xo dat dose of us who did as a professional course and are eating wit it wil not go hungry, dnt 4get dey are praising u but dey woud never open up derez 4 u to know, wisdom is required boss. wel done all d same, wit dis i rest my case..

  42. Dear Engr,
    You are a blessing to your generations and God will reward you for this. Only few people like you can do this for free without charging money.I am saying this because so many people has been misled , ,swindled or duped by quack architect/builder just because you know nothing about building. Imagine someone giving me a bill of 3million to build 3bedroom flat just because i dont reside in the country? Anyway thaks to people like you. May God crown you handwork. this just gives me perfect idea on what to plan for. Thanks….

  43. You are really doing good job here, I just want to add little formula which will be easier. As we have know the total lenght to be 72.5 and the height of the building to be 4.2 from substructure and surface area of a block to be 0.10125, then building surface area can be 72.5*4.2=304.5.10125= 3007 then remove the surface area of the doors and windows which total 644 I.e 3007-644=2363.4blocks

  44. Total lenght multiply by height divided by block surface area,remove doors and windows surface area. I.e 72.5 * 4.2=304.5.10125=3007- 644 = 2363

  45. good job man,but u 4got some details that 85% of block industry in the country uses 8’/420 as 9’/450,at the end of the day u en canter more numbers of block as result ur calculations.u also incure more cost of material,b’cos u use more mortar,cement 2 add strength 2 blocks.address the issue blocks then ur calculation perfect.well done.

  46. I appreciate the job well done. God bless you real good for imparting knowledge on us. But pls how many blocks and cement will take us from DPC to roofing stage. Just want to work towards it before starting as not to get stucked. Please email me. So i can have your email and communicate very well. Thanks.

  47. I appreciate the job well done. God bless you real good for imparting knowledge on us. But please how many blocks and cement will take us from DPC to roofing stage for 3 or 4 bedroom flat? Just want to work towards it before starting as not to get stucked. Please email me. So i can have your email and communicate very well. Thanks.

  48. I learnt this in Tertiary bt it was just highlights and you’ve made it simple and clear…Well done. I’m bit confused with coaches but I understand quite well that each and every country has got its own technical words but meaning the same thing. Anyway thanks buddy

  49. Thanks a lot .Your calculations are steps towards a good quantification.However, to make it more technical, you need to work well on the concrete work;all the lintels must be deducted and 2/2of corners and all the recceses as well. In short, i love ur courage … But for those who posted here,asking for the numbers of blocks they would use for 2bdrms, 3bdrms and 4 bdrms,where are your building plans ? You should know that designs and sizes differ from eah other.You must also provide the topographical information of you site.THANK GREAT BUILDERS!

  50. need clarification regarding the total nos.of layers from the foundation to the roof.
    Earlier mentioned above 4 layers from base to dpc level.4 layers from dpc to base of window,5 layers from base of window to top of window and 3 layers from base of window to top.This will add up to 16 layers.
    but the calculation below mentioned only 4+5+3=12 layers why is this so bearing in mind later windows deducted.kindly clarify.

  51. what is the height of the building?as i can see mentioned as 4.2m can this concur withe number of layers mentioned?

  52. This looks great.. Please i need advice from everyone on 4 bedroom bungalow.. any positive advice is welcome.. from Blocks, Cements, Rods, etc..

  53. Great Job, its amazing how many mason/bricklayer or QS will fumble through wrong calculations and give an overly high estimates of blocks for a single flat and result into over quantity and wastage. Its hard to understand why they cant learn from past quantity quotes or just follow a simple calculations like yours. Its amazing also that you will find out 85% of those who checked or posted a comment here are individuals house owners or prospective ones and not bricklayers/ building contractors themselves because its either most of them are not digital-information literate or are not willing to improve on their mistakes.

    I will share my mobile app for calculating quantity of all kinds of bricks and iron rods or cement for building per space soon, am working on it. check back all.

  54. Please sir, as an upcoming engineer, how can estimate the total cost of a building project to a potential client and prepare my bill of quantity.

    I will be ever grateful if you can help me to solve this quotation challenge. Thanks

  55. Honestly you did a great and wonderful work unknown to professionals of different field,for all those requesting for analysis onbreakdownof number of blocks to be used in their respective buildings, let me make this known to all sundry, building price and estimating analysis isn’t based on just mere assumptions, you must provide a good and reputable plans, because not all structures are builderable,you must provide a good plan so as to give insight to the quantity surveyor to analyse it for you,let me use this medium to correlate my works to all,i design good structures, be it bungalows, duplex, residential or commercial can reach me 08030497621.imo state. That’s where i build right.

  56. It is interested and admireable job,i really thank you sir for your understanding towards this job. I am a freshed building technology student of federal polytecnic Ado, i have question to asked which goes, hwo can i get the easier way of calculating a 4bedroom boungallow?

  57. Sir, you did a wonderful job here, I was worried and I google the required number of blocks, and I was taken straight to your site, you have lessen my burden and I now got the clearer picture and as a layman, I think I have learnt a lot from the responses as well, God will continue blessing you

  58. nice job. but this can be achieved with professionals such as builder,arch ,est survyor, civil engr. pls am using dis medium to be telling nigerians dat is better to engage experts dan rely on bricklayer alone bcos building is a life project. with moral aggrement and little fees u can achieve it. am builder hammed mayowa 08062451800. thank

  59. Man, pls I’d like you to tell me an agreeable ammount a builder could charge a client in order for the client to have the satisfaction that he is not over paying and the builder himself is sure that he’s not cheated?
    Is there also a formula for calculating a builder’s own fee regardless the type/kind of building?

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