Find out how big of an air conditioner you will need in your house with our air conditioner size calculator. Based on different variables in the room you are putting the window unit in, you might get by with a small 5,000 BTU machine. However, if you have a large room that is drafty or has large windows you will need to get a much larger unit, even if the square footage is the same.

BTU stands for British Thermal Unit and is the standard for classifying air conditioner units, even countries that use the metric system. It can be defined as the amount of energy required to heat one pound of water from 39 degrees Fahrenheit to 40 degrees Fahrenheit.

To find out what size air conditioning unit you need choose the best options for each drop down menu. Our calculator will give you a good idea of what size unit you should look at. If you want to save money and be more energy efficient, then you might try some energy saving tips. If the room is drafty or lacks insulation you could seal a door or windows. You could add insulation to walls, attics, and crawlspaces if available. These things will increase your homes energy efficiency and help keep cooling costs and energy consumption down.