What is air conditioner ton

Ton as the name suggests is equivalent to 1000 kg. How is this related to air conditioner?

Actually room air conditioners were derived from the technology used to refrigerate ice or to convert water to ice in earlier times. To relate ice and cooling capacity a formula is derived which says the amount of energy required per hour to make one ton of ice in twenty-four hours. This comes out to be 12000 BTU (British thermal units).

So one ton is equal to 12000 BTU.

Cooling capacity of an air conditioner is measured in tons so one ton AC provides 12000 BTU in one hour.

How much ton AC is suitable for your room

The cooling of a room also depends on other factors other than ton like, insulation, number of windows, sunlight, heat producing appliances in the room like TV, computer etc.

A simple calculation is as follows

Multiply the length, breadth and height of the room (take units as feet). Then divide this by 1000 to get the ton capacity

Example if the room’s size is 10 feet by 10 feet by 10 feet

So 10 X 10 X 10 comes out to 1000, divide this by 1000 the answer comes to 1. So your as tonnage requirement is one ton

Another example room size 12 feet by 12 feet by 9 feet. The multiplication comes out to be 1290. Dividing this by 1000 leads to 1.2. so tonnage requirement is 1.2 ton. If there is direct sunlight in the room and  /or the air conditioner is exposed to sun, or you stay on the top floor where roof heats up, go for 1.5 tom AC otherwise go for 1 ton AC as air conditioners are available in 0.75 ton. 1 ton and 2 ton and above capacity only

Air condition Ton requirement calculator / Chart for room
S no Length* Breadth* Height* Total L*B*H Ton required
1 9 9 9 729 0.75
2 9 9 10 810 0.75
3 10 10 9 900 0.75-1
4 10 10 10 1000 1
5 11 11 9 1089 1
6 11 11 10 1210 1-1.5
7 12 12 9 1296 1-1.5
8 12 12 10 1440 1.5
9 13 13 10 1690 1.5
10 14 14 10 1960 1.5-2
11 15 15 10 2250 2

* In feet, one feet is equal to 12 inches or 30.48 centimeters, 0.32 meters


135 comments to Air conditioner ton calculation

  • sumitc

    My bedroom is 17*13*10. The room is on first floor,getting direct sunlight for whole day. Please suggest me whether I should go for 1.5 ton split ac or 2 ton split ac?

  • P K Mukherjee

    Hello,when I took the connection of cesc, I noticed that it was for 1960 watt with aluminium wire fitted by West Bengal Housing Board.

    Could I use (maximum 3+7 hrs in 24 hrs) a AC of 1 Ton in my one room.Excepting light,fan etc,TV,Fridge & Geyser are also there.

  • Anoop

    My room size is 10*10*10, will 1 ton size AC is sufficient for that ?

  • Raj Kumar

    I want to purchase a AC. My room specifications are 12*10*10. All the walls are not exposed to sunlight. One westside window is there, but is covered with a huge tree, so the sunlight also does not enter in room. I live in Rajasthan. We are two persons with two children. Please suggest me toonage of AC that will be appropriate to me in this room.

  • anil

    my bed room size was 13.6*12sft and second bedroom was 12.6*11.6sft hall was 23*13.6 sft how much ton acs are required for these three please answer me sir

  • arti

    my bed room size is 12x11x10 ft and the room does not have any window…and also there is no source of sunlight. It is on ground floor. i m planning to buy split please suggest me the ton for my room

  • Jahin

    i am confused which ac(window or split) to buy for my room? which ac efficiency is better? Please suggest

  • Srikar

    What will be the effect of having iron almirah in A.C rooms ? Will it increase the power consumption ? We have 3 in one room.

    • living advisor

      Iron Almirah will have no effect on the AC. Where as presence of this will reduce the total cooling area, you will benefit from this.

  • upen

    I have room of 12*12*12 square feet, with no direct sunlight and its ground floor. Hw much ton a.c. required for it for inverter a.c..(sharp inverteda.c.)

  • Piscean

    I am planning to buy an Inverter Split AC in Bangalore for my bedroom (L=12, B=10, Height=9.5 ft). One wall of room is West facing with an open balcony in which I have 4*4 ft sliding glass window and also a wooden door of 7*3.5 ft.

    Room is on 3rd floor and have one more floor above.

    Room has lots of furniture; king size bed with 2 side tables, dresser, entertainment unit with 32′ LED TV, baby crib. Room is occupied by 2 adults and 1.5 year old infant.

    I have shortlisted Daikin brand but confused between 0.75 Ton or 1 Ton models. Technicians who inspected site said both are fine, some say 0.75 is enough some say take 1 Ton to be on safe side. Checking AC tonnage calculators online some suggest 0.75 while others 1 Ton, some put it in between.

    Both have pros and cons; I think 0.75 Ton will consume less power but with temperatures soaring in Bangalore, heard it will reach 40 degrees this April, I am not sure if its correct in longer run. I am unable to take a right call, there is Rs.6K difference between 2 models.

    Please help urgently, quick response if much appreciated!!

  • Vivekanand

    I want to know the tonnage for my bedroom room 10 x 8 x 9(lxbxh).no direct sunlight with window facing south having area 23 sqft. my room also contains a gaming computer and standard insulation . Persons in the bedroom is 2. I live in Mira road near Mumbai. Please suggest me tonnage . I am considering 0.75 to 1 ton ac .

  • shibakali

    I have room of 12*12*10 square feet, with direct sunlight(at evening) and its in first 5 windows(4*3 sq feet each) are there How much ton a.c. required for it?

  • Arvind

    What happens when we buy 1.5ton inverter AC instead of 1ton inverter AC?

  • Lohith Ramesh

    I have LG Monsoon Comfort 1 Ton 5 Star Split A/C (Model LSA3Ew5Z),

    I Need to know how much of power consumption will happen per month, if i use for 8 hours per day.

    Also i need to know if use fan along with for effective cooling how much would it cost per day

    If you share the calcualtion formula for the same, it would great.

    Thanks in advance

    • living advisor

      It will consume around 300 units per month. If you use fan the cooling will be more effective and you can also set the temperature to a higher level by 2 degrees and have the same comfort. This will also save more electricity

  • rakesh

    my room size is 12*10*9 and have two wooden window on west side. It is on top floor and direct sunlight comes after 1pm. How much ton will be suitable?

  • sivaji BasuRoy

    I applied to CESC for enhancement of load capacity for AC.They informed that 2.6Kw is required in addition to already load capacity of 0.3 Kw and charged Rs 12275/-as deposit money in addition to earlier deposit amount of Rs 3000/- I paid the amount.Now they have informed that existing meter have the adequate capacity for additional load requirementMy meter is installed in 1998 with 5-20A,230V,750Kwh & I have two question :-1)If meter/wearing is not changed than can CESC charged that much? 2)Can I use one1.5 ton split AC,one 1ton split AC,one TV,one computer,one fridge,1 fan,4 tube lights at one go in 2.9Kw (0.3+ addtional2.6 kw)capacity?

  • Pankaj Batra

    I had installed 3star Diakin Split airconditioner for room size 12x10x10 is the ac is good enough for above room and is the air condition is best in indian market in term of performance and electricity saving.

  • Vishal

    Which is the correct temp to run the AC in home particularly in the night.

    • living advisor

      Switch on the ceiling fan and set the temperature of AC between 24-26 degrees. This is the right balance between comfort and energy saving.

  • Dear Sir/ Madam,
    Plz provide me the Amps table of non star to 1-5 star AC at same 220 volts
    plz e-mail me me,too.

  • rakesh

    Dear i have my office cabin of 15 x 15 x 10, please guide what ton of ac will be fine and i want to install split ac only as no space.

  • Sohel

    My room size is 15*10*10 and have one wooden window on west side. It is on top floor and direct sunlight comes after 1pm. How much ton will be suitable?

  • Rajesh

    What is the starting power needed for a 1 ton split Air-conditioner with BEE 3 star rating . I am planning to buy Honda generator for my 1 ton ac, will Honda Eu30is (rated output power 2800VA)sufficient to start 1 ton split ac ?

  • aman

    hi pls advise me
    my room size is 12 x 18 x 10
    on d first floor
    i have done false ceiling in d room to reduce heat effect.
    wat size of a/c will hold good 1.5 / 2ton
    and split or window
    at present provision for window a/c is on the corner of the room and dressing room is on the other side of it
    will it affect the cooling of my bedroom
    i hav 2 fans in my room.

  • neelesh

    My room size is 11*13 feet with height 10′.

    The wall and roof gets plenty of direct sunlight and it is on first floor.

    Suggest me the Split ac with brand and Ton capacity .

    My preference are in order HITACHI,Panasonic and Voltas

  • Edwin

    i am using LG 1.5 ton split and window ac. split ac consuming more power than window ac. its true ? r my split ac consuming more power ? split ac consuming 2 units/ hr(9 amps) (continues running) window ac consuming 1.8 units/hr. this is correct consumption….

  • Kamal

    My room is 12 x 11 x 10 plus space area is 5 x 3 x 10. It has 3 sliding aluminum windows facing the north direction where split ac is fixed above. Should i go for 1 ton or 1.5 ton as we only use air conditioned in night only. Secondly, I need energy saving 3 or 5 star unit which runs 6 hrs daily at night timings for 9 months in the season year. My brand choice is Panasonic or Daikin… Which one is the best reliable in long run?

    Waiting for reply via email.
    Thanking you,

  • Harsh

    Sir i want to know that my room size is length 20 ft and width 18 ft so 1.5 ton AC is enough for cooling my room . sir please suggest me

  • Rahul


    What the difference between inverter ac and star rated ac , i have to buy an ac of 1.5 ton for my room if i buy inverter ac of 1.5 ton how much unit it takes for one hour .and which is the best spilt ac to buy (copper

    • living advisor

      Inverter AC is new technology introduced but it is costly and requires power supply with less fluctuations. The tonnage is variable in Inverter AC as compared to fixed tonnage but the difference does not converts to more savings in electricity bills. Setting room temperature at 26-27 degree Celsius as compared to 22-23 Celsius will save more power (about 30%)

  • praveen

    room size 12.4 x 11.5 x 10 ft
    1 window 5 x 4 ft
    1 entry door
    1 attached bathroom door
    02 persons
    no tv , refrigerator….etc
    01 tube light
    01 fan
    direct sunlight never enters room from any side
    top floor
    place- jamnagar normally not so hot compared to north and other regions.
    jamnagar surrounded by arabian sea.

    kindly suggest right tonnage of Ac

    i am planning for 1 Ton 5 star Ac of Lg 2014 moonsoon cool feature.

    • living advisor

      As room is bigger 1.5 ton AC will be better. Power consumption will be the same. 1.5 ton AC will obtain the set temperature earlier and will shut off while 1 Tom AC will take a long time to coll. So more or less the power consumption will be the same. Added advantage is the room will get cooler faster.

      You can same more power by setting the room temperature at 25-26 degrees than setting it at 22-23 degrees. So the suggestion go for 1.5 tom AC and save power by setting temperature suitably.

  • peter

    I had 10 Amps Elecrical meter can we use 3 nos, 1.5 tons Air conditioner

  • My room is on the top (4th) floor, with windows in the East
    and North. It has 2 iron almirahs, 2 wooden medium-sized book
    cases and a single divan with a chair and small table with a 100 books.
    My room’s approx measurement will be 12′ by 11′ and height 12′, maybe a little
    less…which tonnage of AC should I but? I am thinking of
    buying a split Ac , Blue Star…I will use it for max 8 hours a day, only in summer
    afternoon: 3 hours, and st night: 5 Hours…

  • Anand

    I bought a VOLTAS 1.t 123LYE, Uses it ofr about 7-8 hours at night, My consumption daily has gone upto 3-4 units per day, Going by meter readings, Earlier we use to get about 7 UNits per day, with AC it now averages to 10. Not much, My room is 12x10x10

  • sudeep

    I need to install split ac on my room?
    I have 2 KV electric connection. Is it possible install 1.5 ton split ac without increasing load to electric meter. or i just need to change wiring

    please advice me because i know this type of problem is very common in India specially in medium family

  • sp

    Would 1 ton ac be enough for a room f size 11×11 and 11×13?

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