Room Size & BTU Calculator

Enter the length and width of your room to estimate the air-conditioner capacity you need.

BTU measures the cooling capacity of an air-conditioner. A unit that is too small may struggle to cool the room, while an oversized unit may use more power than necessary.

Enter the Room Size

Measure the inside length and width of the room in metres.

Room length

metres

Room width

metres

Calculated floor area 0.00 m²

Select the Room Condition

Choose the one option that best describes the room.

Large windows or direct sunlight Large or oversized windows that receive strong sunlight. Open to another room or area The room has a wide opening into another room, office or bathroom. Ceiling higher than 3 metres The room has more air volume because of a high ceiling. Extremely hot or cold The room becomes unusually hot or cold during the summer or winter. None of the above The room has normal windows, ceiling height and temperature conditions.

Recommended Air-Conditioner Size

How to Measure

Measure the room from one inside wall to the opposite inside wall.
Enter the length and width in metres.
Select one room condition that may increase the cooling requirement.
Press Calculate BTU Size to receive the recommended capacity.

Please note:
This calculator gives a practical estimate. Building insulation, room use, number of people, equipment, windows and climate can affect the final requirement.

Common Room Size Examples

These examples give you a quick idea of common air-conditioner sizes.

9,000 BTU Rooms up to 18 m²

12,000 BTU Rooms up to 25 m²

18,000 BTU Rooms up to 36 m²

24,000 BTU Rooms up to 48 m²

Room Size & BTU Calculator

Enter the Room Size

Select the Room Condition

Recommended Air-Conditioner Size

Common Room Size Examples

Ready to Find the Right Aircon?