BTU Calculator

Need to calculate how many BTUs your air conditioner needs to be? Our handy calculator will give you the BTU value required for your room so that you can choose the right air conditioner to achieve optimal cooling performance.

How to use this calculator

  1. Enter the length, width and height (in metres) of your room in the provided fields
  2. Next, enter the number of people and devices that will occupy the room in the provided fields (these can all affect how powerful your air conditioner needs to be)
  3. Then, hit 'Calculate' and we'll tell you how many BTUs are required for your room!
  4. Now that you have the right BTU for your room, shop our range of portable air conditioners to find the perfect unit for you.

Room Size:

Length (m): Width (m): Height (m):

Heat Sources:


Appliances (TVs, computers etc.):

7,000–9,000 BTU

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10,000–12,000 BTU

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12,000+ BTU

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All Units

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There are lots of factors which can affect the exact BTU requirement for a room, such as wall and ceiling insulation, the direction the room faces, the size and condition of windows, and more. If in doubt, we recommend choosing a slightly larger unit to be sure that it will effectively cool your room.

Still need advice?

We're happy to help—please get in touch with us and we'll be able to give you more advice for deciding on the right air conditioner for you.

What does BTU mean?

BTU stands for British Thermal Unit. This is a way to measure how much energy something has. For example, one BTU is the amount of energy it would take to heat up one pound of water by 1° Fahrenheit. People usually use BTUs when they talk about things that heat or cool, like air conditioners.

Our air conditioning buying guide contains more information on air conditioner power requirements and everything else you need to know when deciding on the right air conditioner for you.