3 Simple Steps to Size a Ceiling Fan

Are you still feeling the heat even after you’ve installed a new ceiling fan in your room?

Perhaps you’ve not taken the size factor under consideration while choosing a ceiling fan. Manufacturers offer different sizes of ceiling fans according to the room size and they have their own standards to measure the dimensions of the room.

ceiling fan room size

Source: WestinghouseLighting.Com

The reason why size becomes so important, is ceiling fans have limited airflow capacity that’s largely affected by the length, width and height of the room. There are many factors affecting it, such as:

  • Improper distance from the ceiling – that’s when you get the wrong downrod; or the low ceiling doesn’t offer enough space to circulate the air properly.
  • Inaccurate distance from the floor – more than 10 feet in a smaller room
  • Dimensions of the blades – large blades in small rooms don’t give the right airflow.

People don’t often consider dimensions when they choose a ceiling fan, just like you did, and end up getting a good fan in the wrong room.

Do you know that the ceiling fan with relevant size can make your room 8 degrees cooler than the actual room temperature? Surprised? Well, you can feel the same if you learn how to install a ceiling fan according to the size of your room. This post will take you through those simple steps:

Step 1: Determine the Blade Span

Calculate the area of your room

  • Measure the length and width of the room in feet.
  • First of all, you need to calculate the length and width of your room. Measure the length from one wall to the opposite wall. Measure the width in the same manner.
  • By multiplying the length of the room with the width, you will get the answer in square feet.

Calculate the diameter

Measure the length in inches

  • If you are choosing a ceiling fan with three blades or five blades, measure the distance from the end of the blade to the center of the fan. Then multiply the result by 2.
  • If it’s a ceiling fan with 4 blades, measure the distance from the end of one blade across to the end of the blade at the opposite side of the ceiling fan.

Recommended blade spans for different room sizes

  • For rooms up to 75 square feet; 29 – 36 inches blade span
  • For rooms 76 – 144 square feet; 36 – 44 inches blade span
  • For rooms 144 – 225 square feet; 44 – 54 inches blade span
  • For rooms 225 – 400 square feet; 54 – 72 inches blade span
  • For rooms bigger than 400 square feet; two fans with 50 – 72 inches blade span

Source: www.apartmenttherapy.com

Step 2: Determine the Height for Mounting

In this step, you have to measure the height of your room. It will help you determine how high you should hang your ceiling fan. Keep these two situations in mind

  • You room may have a straight ceiling or slope ceiling
  • You room may have a low ceiling

For straight ceilings

There are two kinds of mounts available for straight ceiling; standard and flush.

  • Standard mount is for rooms that have a ceiling over 8 feet. Make sure that the distance from the floor to the tip of the blade must be 8 feet or more.
  • Flush mount is for low ceilings up to 8 feet. For such rooms, make sure that the minimum distance between the floor and the blade must be 7 feet; otherwise, it’s inappropriate to hand a ceiling fan.

For Slope Ceiling

Use a slope mount to hang your ceiling fan. Make sure that the fan should be mounted at the middle of the room at an appropriate height. The distance from the floor to the fan blade must be minimum 8 feet.


  • Choose a low profile ceiling fan for low ceiling rooms up to 8 feet
  • Choose a ceiling fan with downrod for rooms above 9 feet
  • Make sure that the distance of the fan blades from either wall must be at least 18 inches.

Step 3: Choose The Right Downrod

While choosing a downrod for your ceiling fan, keep the room’s height in mind. You have to mount your ceiling fan in such a way that it should maintain a safe distance from your head.

Following information will help you choose a downrod of appropriate size, according to the height of your room:

  • For low-ceiling rooms (less than 9 feet height): Choose a low profile ceiling fan with flush mount. The downrod length must not exceed 3 inches.
  • For 9 feet ceiling: You can use a downrod of 3-6 inches.
  • For 10 feet ceiling: Choose a 12-inch downrod.
  • For 11 feet ceiling: Choose an 18-inch downrod
  • For 12 feet ceiling: Choose a 24-inch downrod
  • For ceilings 13 feet or higher: Choose a 36-inch downrod.

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May I know does the distance from the walls to the tip of the blades matters?

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