Air Conditioner Size Calculator 

Saad Iqbal | 🗓️Modified: January 3, 2023 | ⏳Read Time: 1 min | 👁Post Views: 281

Here is a tool for an air conditioner size calculator that takes the input including size of room, no of persons, to temperature and calculates the AC tonnage required:












AC tonnage required: tons

How to use Air Conditioner Size Calculator

This calculator allows the user to enter the length, breadth, height, number of persons, and maximum temperature in the room, and then click the calculate button; it will show you the required tonnage of AC for your room.

The size of air conditioner or AC tonnage depends onfollowing factors:

  • length of room in feet
  • Breadth of Room in feet
  • Height of Room in feet
  • Number of persons
  • Maximum temperature in degree Celsius
    The formula to calculate AC tonnage required :
    AC Tons = ((Length×Breadth×20)/12000)+factor for No of Person+factor for Temperature+factor for Height of room

Factor for number of person
0.3 Up to 3 people in a room
0.07 for each extra person in the room. ex. (0.3 + (0.07 * No. of Extra person))
Factor for temperature
0.5 If the highest temperature in summer exceeds 45 °c
0.4 If the highest temperature in summer between 41- 45 °c
0.3 If the highest temperature in summer between 36- 40 °c
0.2 If the highest temperature in summer lesser than 35 °c
Factor for height of room
0 Room Hight up to 8 feet
0.1 for each foot if the ceiling is over 8 feet tall

Steps to estimate AC tonnage for a room

When it comes to choosing an air conditioner for your home or office, one of the most important factors to consider is the tonnage of the AC unit. But what does AC tonnage mean, and how do you calculate the right tonnage for your room?

AC tonnage refers to the cooling capacity of an air conditioner, which is measured in tons. One ton of cooling capacity is equal to the amount of heat that can be removed by melting one ton of ice in a day. In other words, a 1-ton AC unit can remove 12,000 BTUs (British Thermal Units) of heat per hour.

Why is it important to choose the right tonnage of AC for your room? If the AC unit is too small, it will struggle to cool the room, leading to inefficient performance and higher energy bills. On the other hand, if the AC unit is too large, it will cool the room too quickly, leading to short cycling (frequent turning on and off) and higher humidity levels. Both of these scenarios can result in discomfort and reduced air quality.

So, how do you calculate the right tonnage of AC for your room? Here are the steps to follow:

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  1. Measure the size of the room: The first step is to measure the length, breadth, and height of the room in feet.
  2. Determine the number of persons in the room: This will help you calculate the heat load due to people in the room.
  3. Determine the maximum temperature in the room: The higher the temperature, the more heat the AC unit will need to remove.
  4. Use the following formula to calculate the AC tonnage required: AC Tons = ((Length×Breadth×20)/12000)+factor for No of Person+factor for Temperature+factor for Height of room

Here are the factors to consider for each of the variables in the formula:

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  • Factor for number of persons:
    • 0.3 Up to 3 people in a room
    • 0.07 for each extra person in the room. ex. (0.3 + (0.07 * No. of Extra person))
  • Factor for temperature:
    • 0.5 If the highest temperature in summer exceeds 45 °c
    • 0.4 If the highest temperature in summer between 41- 45 °c
    • 0.3 If the highest temperature in summer between 36- 40 °c
    • 0.2 If the highest temperature in summer lesser than 35 °c
  • Factor for height of room:
    • 0 Room Hight up to 8 feet
    • 0.1 for each foot if the ceiling is over 8 feet tall.

For example, if the room is 10 feet long, 10 feet wide, and 8 feet tall, and there are 5 people in the room, and the maximum temperature in the summer is 40 °c, the AC tonnage required would be calculated as follows:

AC Tons = ((10×10×20)/12000) + (0.3 + (0.07 * 2)) + 0.3 + 0 = 3.3 + 0.5 = 3.8 tons

In this example, you would need an AC unit with a tonnage of at least 3.8 tons to adequately cool the room.

It's important to note that this is just a rough estimate and the actual tonnage required may vary based on factors such as the insulation of the room, the number of windows, and the orientation of the room. It's always a good idea to consult with a professional.

Typical Value sof AC Tonnage Calculator

Here is a table showing the required number of AC tons corresponding to typical room sizes in square feet:

Room Size (sq ft)Required AC Tons
100-1501.5-2
151-2502-3
251-3503-4
351-4504-5
451-5505-6
551-7006-7
701-10007-10

Keep in mind that these are just rough estimates and the actual tonnage required may vary based on factors such as the insulation of the room, the number of windows, and the orientation of the room. It's always a good idea to consult with a professional HVAC technician to determine the precise tonnage required for your specific situation.

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