When buying an AC in India the most important question that many consumers have in mind is how much ton AC should they buy and whether the AC will be sufficiently enough keep the room cool. If you ask this question to the salesman most probably they will try to sell you the maximum ton AC, which in fact will be more than required to cool the room.

So how does one calculate how much ton AC a room requires?

The answer is very simple. To find the ton AC required you should know the length, breadth and the height of the room. Once you have the figure (in feet) just multiply all of the three to get a total.

So the formula goes Total = Length (feet) x Breadth (feet) x Height (feet)

Now compare the total that you have arrived according to this chart.

Total Ton AC Required
Less than 729 0.75
Between 729 and 810 0.75
900 0.75 to 1
1000 1
1089 1
1210 1 to 1.5
1296 1 to 1.5
1440 1.5
1690 1.5
1960 1.5 to 2
2250 2


There are several other factors that you also need to consider for effective AC cooling.

  • The number of Windows in the room.
  • Application that produce heat such as TV, Desktop etc.
  • If the room gets too much sunlight.

which ton AC to buy

Once you know the total you can easily find the Ton AC required for your room.

Published by Gogi Rana

Founder and Chief Editor - gogi.in

Join the Conversation


Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

  1. May I know how many machine required in 1.5 ton and 2 ton. our room size 40×40 hight 9 feet

  2. Hello, My room size is @4*13*9.5 sqft., South-east side of the house. a eastward window measuring 5*4.25 sqft. and 4 doors (one with corridor and other with attached bath, the 2 others with two different rooms). It’s in 1st floor and another floor is above it. South side is covered with bath and corridor. there is a fridge of 175 watts in the room with a LED Tube and fan. How much tonnage of ac shou I required? Thank you in advance.

  3. Hi sir my room is 16*20*13 size so please suggest which ton AC is suitable for room in Windows ac

  4. Hello sir my room 14×15×14 and 2nd floor and direct sunlight in whole room so 2 ton ac is suitable for me or i use any other option

  5. room size 12×10×11…two windows (5×4) facing West and South direction ….floor and west wall and window on direct expose to sunlight…
    plz suggest the tonnage of AC

  6. My room size is 18*14*10 which is on 1st floor….which tonnage capacity required and which brand? I have already install hitachi 1.5 ton in this room..but it is not provinding comfort…

  7. hello sir,
    i’m planing to buy a new ac for my room with dimensions 11*12*10, though there is one floor above the room but the backside of the room remains totally exposed to the sunlight, the whole day. the room has 2 doors and 1 window. So, what points must be kept in mind while buying an ac, also what should the preferred capacity.
    thank you

  8. my room 12x12x10. direct sun light on roof only not on wall. AC usage mainly in night. can i go for

    Voltas 1.2 Ton 5 Star BEE Rating 2018 Inverter AC – White (155VLZC, Copper Condenser)

    suggest plz.

  9. My room is 15×10×10 which ton ac. Is suitable for it nd there is two window 4×4

  10. Superb! Very neat and simple article. I’ve read some other articles and tried AC calculators too. But the answer is not satisfied. As you have given the tonnage table now I am fully satisfied about my calculation is right. Thank you very much!

  11. Hello Sir/Madam,

    We live in Adilabad hilly ghat area where temperature is reaching nowadays 42C.
    I have hall dimensions as 12 x 22 x 11 (in feet)
    Room No. 1 – 12 x 12 x 11
    Room No. 2 – 12 x 13.5 x 11
    Room No. 3 – 12 x 12 x 11

    Kindly suggest the required energy saving Split AC …

    Very Kind…


    1. Volume Method : Alternatively, multiply the length, breadth and height of a room (in feet). Divide the answer by 1000. This is the tonnage required.
      Using Volume Method :

      The room is 10 feet wide by 15 feet long and height is 20 feet (double height).

      That means 10×15 x 20 = 3000 cu.feet.


      We get 3 T

      Choose an AC which is 3 Tonnes.

  12. my room size is 14×11×10 ground floor
    recieve no sunlight from any side and also there is first floor on its roof
    is 1 ton or 1.2 ton ac will be sufficent or not
    please tell

  13. My room size is 13ft (length)*9 ft (breadth)*9 ft (height) top floor n direct sunlight.is 1ton inverter AC is sufficient?

  14. My room size is 15*14*10 top floor with 1 led tv ,almirah,1 large bed..how much ton is required

      1. we are from Bangladesh,Rajshahi.We have a two stroyed Mosque. Ground flour’s size is 73 feet length and 43 feet wide.How many split a c require?

  15. Ground floor home , 15x12x11 room size ,
    LED TV , 4 doors ,2 windows , and direct sunlight on floor
    Which ton of ac required that size!?

    1. 1.5 ton is sufficient, but will take a little longer to cool than average room. Don’t run your 1.5 ton AC on temperature less than 24 in Daylight hours to reduce load on compressor.

  16. I live in kolkata. I am having 3 rooms
    a. 10*11*10 (ft)
    b. 10*7*10(ft)
    c. 12.4*11*10 in a series. i have to pass thru room no b, if i want to access room c from room no a, now this is the scenario. Now please suggest me best budgetary cooling solution for these 3 rooms.

    1. Room A and C will work fine with 1.2 ton unless there is frequent opening of doors. In room C 1.5 ton is best. However if you keep all 3 AC running together then Room A and B can have 1 ton AC. But 1 ton and 1.2 ton there will not be much price difference, so go for 1.2 ton for better cooling in KOLKATA during high humid days.

  17. Sir my room size 10 by 10 how many ton ac are required please help me to solve this confusion.

  18. Sir my room size 11 ft lenght 13 ft breadth 12 ft height kitne tan ka ac suitable hoga

  19. Sir already i had an ac(1.5 ton blue star ) at my room size 16 * 16 * 10.25. it is in ground floor with 2 floor above it.

    I had plan to install a new ac to another room 11 * 16 * 10.25.

    My query is:
    1. what should i do? either i swap the existing ac to small room n get bigger one for large room or Is that existing ac is enough for that room?

    2. suggest me size(ton) of ac for both room? kindly.. thnx in advance

    1. Fit 1.5 ton blue star in 11*16*10.25 room and fit 2 ton ac for 16*16*10.25 room as 1.5 ton is not enough for bigger room.

  20. My room size 11.6 ft(length)x11.6 ft(breadth)x 9 ft(Height)but not cooling properly .There is not any floor on my roof & heated by sunlight. Is my 1.2 ton ac sufficient for my room.?

    1. My room size is 20ft length….. 10 ft breadth…. and 10 ft height…. how much tonn a.c is suitable for me….? And also suggest good one a.c also

      1. my room size is 13*20*10 so how much ton ac is required for it.and the room is at 1st floor and direct sun light.would u suggest me ?

    2. It is on the upper limit of 1.2 ton Ac, So cooling will take time. Try to do some modifications like:
      Making sure that outdoor unit is in shade all the time. Also doors and windows are closed. make sure filters and fins are clean. Also make sure outdoor unit fins are clean. Clean the fan of indoor unit too. This shall improve the system a bit.
      Also make a note to get gas pressure checked. If you are facing ice problem in return line of AC (fat line) or in liquid line after 10 15 mins of AC running then GAS is low.
      But firstly clean and shade.

  21. Hi,

    we live in Bangalore My room volume comes to 1287 with approx 198 covered with wood work. might add a LED TV in future. There is one floor above us and there is no direct sun exposure, will be used between March to June months, so not looking for a great energy saving. Ideal temp maintained should be 22 to 24. Should we go for 1 ton or 1.5 ton?

    1. My room size 12 ft (length)x16ft(breadth)x 11 ft(Height). & it is 1st floor having three floor more and there is no direct sunlight exposure
      . Is Window 1.5 ton ac sufficient for my room.?

  22. I have a hall of 40x25x10 how many ac and of what capacity I should use to cover this area please answer it’s urgent

  23. A big hall is to be air conditioned cooling load is 18 tons will it be beneficial to use 12 window air conditioner unit of 1.5 tons capacity?

  24. How to calculate the tonnage requirement for badminton courts for which the total is above 40000 cft as the height of the court is 30 ft

  25. I need AC TON CAPACITY for room size(cool room for egg storage need Temperature 18’celcius) 27*52*9 feet,please reply the above area

  26. My room size 24×16×10.5 and four door and one window on 1st floor . Please advice is how much ton AC will be suitable.

  27. Our room is 30x33x9 on Ist floor of 7 storey building. It’s has good ventilation with opposite side windows. We’ve been using 1.5 ton since last 20 years but I feel 2.0 ton would be better. Thinking of Hitachi. Kindly suggest. Thanks

  28. In simple words it packs a bigger engine.

    Just like your car/bike , the bigger the engine the more the power/pickup/top speed.

    But efficiency is another parameter which will be calculated by the ISEER rating.

    For a room little bigger than a double bed 1 Ton is sufficient , but if you are using it in your lavish master bedroom you will need to go anything equal or above 1.5 Ton.

    For a 280 sq feet room my AC does the job , considering that it is a bedroom and always closed when the AC is on and secondly we don’t reside on the top floor where the AC has to work really hard to cool the walls continuously heated by sun.

    Just by my experience i have a Voltas 1.5 Ton 5 Star Split AC Aluminium, 185JY, http://amzn.to/2qxXmCQ ,its quite sufficient for my requirements.

        1. While asking for tonnage define your location because heat load is mainly depends on location. In India you can take 1tr/120sq.ft. (for commercial). And it is different for different sectors.

    1. For a 280 sq feet room my AC does the job , considering that it is a bedroom and always closed when the AC is on and secondly we don’t reside on the top floor where the AC has to work really hard to cool the walls continuously heated by sun.

      Just by my experience i have a Voltas 1.5 Ton 5 Star Split AC Aluminium, 185JY, http://amzn.to/2qxXmCQ ,its quite sufficient for my requirements.


  29. My room size is Length 20 feet
    Hight 10 feet
    Width 12 feet one door two window
    Top floor
    Please tell me which ac is better and how much ton ac is required

    1. My room size is Length 18 feet
      Hight 10 feet
      Width 12 feet one door two window
      Top floor
      Please tell me which ac is better and how much ton ac is required

    2. Length 18ft and width is 13 ft room terrace flat. 1.5 ton ac comfortable yes or no?

  30. Room size
    36 inches length
    23 widths
    12 heights

    How much ton AC required and how many??

  31. My room 10f*15f*9f pl sajestion of my room is requred ton my room 3 window and 2 main door

  32. My bedroom size is 20ft x 14.5ft x 10ft with 3windows n 2doors. It gets direct sun heat from the west side for a long time during the day. What should be the tonnage of my AC? Pls suggest. Thanks in advance.

  33. I have two rooms (12x12x9) connected with a common door. Will it be ok if I fix 2 ton split (sharp)?

  34. sir we need to ductable unit for the area 208080.
    lenght 51 ft, breadth 51 fts and height 80 fts.
    what is the cfm and btu and tons required.