How to Estimate Aircon Size? The Definitive Guide

Air Conditioners are common cooling machinery found installed in homes, offices, and laboratories. In this heat, we cannot deny their importance. It has made our life easier by filtering out the cool air for us so we can get a comfortable environment to work in.

The important thing you should keep in mind while buying an aircon is its size. Size matters a lot and if you think that your air conditioner isn’t working properly, check its size as chances are that your room may be bigger than the AC’s size.

But how to determine the AC’s size in your room? And at what place should it be installed for better air conditioning? We will tell you in this article. So let’s start.

A Complete Guide For the Aircon Size And How To Estimate It

When we talk about the size of Air Conditioners, it does not mean that you have to measure their length and width. Rather the size of an aircon is measured in BTU, simply known as the British Thermal Unit.

Calculate The Size of The Room:

First of all, what you need to do is measure and calculate the size of the room where the AC has to be. You have to calculate your room size in square meters by multiplying the length and width of the room.

When you get your answer, you have to multiply it by 25 BTU. The final answer will be the cooling capacity that your room needs.

For instance, the length of your room is 25 meters and the width is 18 meters. The product of these two numbers will be 450 square meters. After multiplying 450 with 25 BTU, you will get 5400. 5400 BTU is the size of the air conditioner you need for that room.

Can A Small-Sized Air Conditioner Work?

You must be wondering whether you can get a smaller size than your estimated one. So the answer is yes and no. The smaller-sized air conditioner will work just as well as a bigger or perfect-sized one.

But the smaller air conditioner will use more electricity and you will get a huge electricity bill. A smaller size will take more electricity to cover the needs of your room but it will not work as efficiently as any compatible-sized air conditioner. So choose wisely before buying a good sizing.

Can A Big Air Conditioner Work?

There is a mixed answer too. Big-sized aircon may cool your room more quickly but it will also be the reason for humidity produced in the room. The air conditioner will not run long due to its large cooling capacity but as soon as you switch it off, your room will get more moist and humid.

Importance of Right-Sized Air Conditioning:

A right-sized air conditioning is more important than you think it is. If you do not get enough cooling in your room, then you are wasting your money on the aircon as well as huge electricity bills.

A right-sized aircon will help you with greater efficiency and you will not have to worry about enough cooling in your room. A perfect size will function with great efficiency. Air conditioners work more efficiently when they have good compatibility with your room size.

Best Air Conditioner Sizes for Your Room:

You can see a chart available for estimated aircon sizes for a room. We have made a list for you if you want to know which size will be best for your room.

This measurement is the same for every AC. If you calculate your room size, you will know the exact size of the air conditioner that is required there. You can measure your room size by yourself or you can take help from a professional.

Other Factors To Keep In Mind While Estimating The Size Of An Aircon:

Your room size is not the only thing that matters when buying the perfect-sized air conditioner. A lot of other things also determine the cooling in your room. If you think you have a perfect-sized AC but it is not cooling as it should, try checking these other possible things.

Number of People In A Room:

Ever heard about body heat? A big reason why your AC is not cooling can be the number of occupants in a room. If a lot of people are sitting in a room, they emit body heat that doesn’t let your AC cool the room. So you should up the size of the AC or lessen the people’s burden on the room.

The temperature of The Room:

If your room is situated in a place where it gets direct sunlight, that can also be a reason that your air conditioner is not working properly. Try putting shades on the outside of the room where it is getting the sunlight.

You have to take the temperature of your room as low as possible for better cooling. Pair a ceiling fan with it and cover your windows too.

Other Sources of Heat:

Stop the other sources of the room where your AC is located or try to buy a bigger size one. The lights in your room can also add extra heat so try to use light bulbs with low voltage. Some machinery can also fluctuate your AC’s cooling capacity.

If you live in a studio-type apartment, try buying a bigger size AC as you have to cook in the kitchen that can add extra heat to your room.


A good size air conditioner is the only option that will save you from this heat. Make sure you estimate the right size for your aircon while buying it. So what are you waiting for? This is your sign to upgrade your air conditioner. Hurry up before it is too late.

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