When you decide to purchase an AC for your home, the first thing you check out is the tonnage required.
It would be excellent if you knew how to calculate the tonnage on your own. Yes, you have come to the right place as our AC tonnage calculator will help you do so within a few seconds.
What capacity AC is required for the room?
Use our calculator to find out the AC tonnage required for your room.
Step 1: Enter the room area in square feet.
Step 2: Enter the height of the ceiling in feet.
Step 3: Choose the climate type between ‘Hot’ and ‘Average.’ Generally, the ‘Average’ option is the right one.
Step 4: If there is no other room above, your ceiling receives direct sunlight. Select ‘Yes,’ otherwise, you can select ‘No.’
Step 5: Provide information on whether direct sunlight is on the walls in the South, West, or South-West direction.
By providing this information, you can calculate the tonnage required for your room and the size/capacity of the AC necessary.
How do I calculate AC tonnage?
The mathematical calculation to determine the tonnage required for an AC can be a bit confusing as it involves using terms like BTU (British Thermal Unit), etc. For the record, 1 ton equals 12,000 BTU. First, however, we shall look at a simple way to calculate the tonnage necessary for our rooms.
AC Tonnage Calculation Formula
Calculate the volume of the room (length x breadth x height) in cubic feet. Divide the volume by 1,000, and you get the AC tonnage required for your room.
However, this calculation is an average figure because many other aspects affect the AC capacity required for your room. These factors are as follows.
- The overall climate of the place you live
- Whether you live on the top floor or there are floors above your room (whether sunlight falls directly on your ceiling)
- The positioning of the windows (direction is crucial, and whether sunlight falls on the room’s walls)
- The number of people occupying the room
- The furniture and other electrical/electronic equipment in the room
Our calculator considers all these aspects when calculating the tonnage required for the room. The air conditioner size depends on the required tonnage.
This table will help you to arrive at the right AC size for your room. We make the following general assumptions.
- The number of occupants in your room is three to four.
- The height of the ceiling is 10 feet (average height of ceilings in Indian rooms).
| Area | Cooling Requirement | Recommended AC tonnage |
| AC for 100 sq ft | 0.9 tons | 1 ton AC |
| AC for 120 sq ft | 1.0 tons | 1 ton AC |
| AC for 150 sq ft | 1.3 tons | 1.5 ton AC |
| AC for 160 sq ft | 1.4 tons | 1.5 ton AC |
| AC for 170 sq ft | 1.5 tons | 1.5 ton AC |
| AC for 200 sq ft | 1.7 tons | 2 ton AC |
| AC for 250 sq ft | 2.1 tons | 2 ton AC |
| AC for 300 sq ft | 2.6 tons | 2.5 ton AC |
| AC for 400 sq ft | 3.4 tons | 3.5 ton AC |
These cooling requirements and recommended tonnage will change if your room has direct exposure to sunlight either from the ceiling or from the walls (south, west, or south-west directions).
The thumb rule for calculating these figures is as follows.
- If you live in places with a hot climate, add 0.10 tons to the cooling requirement.
- If your ceiling has direct exposure to sunlight, add 0.20 tons to the cooling requirement.
- If your room has walls exposed to sunlight from the south, west, or south-west directions, add 0.10 tons to the cooling requirement.
- The recommended tonnage should be at the next higher decimal. For example, if the cooling requirement is 1.7 tons, you should go for a 2.0 ton AC. However, if the requirement is 1.6 tons, you can settle for a 1.5 ton AC.
So, if your room area is 150 square feet with walls facing the west and no floor on top, your cooling requirement increases to 1.6 tons. Thus, you will need a 1.5 ton Air Conditioner for your room. However, if you reside in a hot place, the cooling requirement increases to 1.7 tons, and hence, you have to invest in a 2 ton AC.
Here are some frequently asked questions on calculating AC tonnage?
How do you calculate the room size for AC?
However, you can enter the ground area (Length x Width) and the ceiling height separately when using our calculator.
I am planning to install an air conditioner for my kitchen. It is 75 sq ft with a ceiling height of 8.5 ft. None of the walls or ceiling are exposed to direct sun. What would be your recommendation that will compensate for the heat generated while cooking.
Hello Chaitanya,
Excellent information, that too easy to understand for non- technical persons.
Need your help to understand about who has the choice to decide capacity of Air conditioner units – in VRV SYSTEM? In terms of Indoor units and outdoor units. We have a residential individual house – 3500 sq ft area requirements for cooling – average height of 10 ft.
As per your calculator it’s 29.8 tons – BINGO – the same is calculated by vendors.
Now, situation is following….
Vendors want us to buy 30 ton capacity outdoor units mentioning that company will not allow to install lower capacity than this! – where in we are not over 5 persons in routine days and once a month may be 15 for a dinner!
1. Can we calculate some factor where 20 – 30% less capacity is acceptable in Out door units?
2. Can companies enforce to set up higher capacity unit?
For 3500 Sqft, it is better to go with cassette style air conditioners. Daikin and bluestar are popular Cassette air conditioners. As you have mentioned that the occupancy will be more in some days do not go for lower tonnage. Also, most of the brands now are making variable tonnage air conditioners so you can easily adjust the operating capacity.
My Hall,Dinning space and Kitchen open. area Aize approxi 750sq feet
then which AC is recomannded and Which Copper pipe we used for 2 Ton Ac and ELE.CABLE WE USED.
PL GUIDE US
my room volume is 12*14*10.5 cubicfoot and the room contains two almirahs and a divan bed holding the volume approximately 50 cubic foot. what will be the ideal ac for my room
Hi Chaitanya!
Thank you for the information provided here! I’m planning to buy an a/c in the next 2 days. Can you provide your tonnage recommendation for my room that has these factors?
Room Size = 13 * 16 with False Ceiling
Windows = East Facing
Four occupants including 2 children.
We, currently, use a 2 ton Voltas that some times feel too cold for the children due to the chillness. We also use two fans that is directly above our beds, in addition to the A/C.
For a room size of 13 x 16, 2 Ton AC is the ideal choice. If you go for 1.5 Ton you might face cooling problems in Peak Summer season. You can buy an 2 Ton Inverter AC that can maintain a constant temperature throughout the day. Unlike normal ACs, the Inverter Compressor won’t on/off, they operate constantly.