*What is the best ceiling fan size?*

We can agree that you cannot choose any ceiling fan size. You will need to make a fan the size of the room you want it to be. A **properly sized** A ceiling fan can provide ventilation and improve comfort year-round.

We are going to look at all ceiling fan sizes and a . will use ** ceiling fan size guide** (found below) to choose the size of ceiling fan you need adequately. There is also an important part of this process

*how to measure ceiling fan size*(You’ll find a step-by-step method for both odd-number and even-number blades; you’ll need to determine the diameter of the blade).

Here’s the deal:

Many homeowners get the ceiling fan sizing wrong. They buy a ceiling fan that is either too big or too small. *How to determine ceiling fan size?* Navigating Ceiling Fan Blade Diameter, CFM, and Room Square Footage isn’t that easy, as you might imagine; That’s why resizing mistakes are made.

*Example:* What should be the ceiling fan size for a 12×12 room? A 48 inch fan is huge. A 36 inch fan is too small. The 42-inch ceiling fan is perfect for a 12×12 room.

As you can see, ceiling fan size is measured in **Blade diameter**, We talk about 36-inch, 42-inch, 48-inch, 52-inch, 60-inch ceiling fans etc. In HVAC, however, we primarily focus on the air flow generated *(measured in CFM or cubic feet per minute)*,

The diameter of the blade (the size of the ceiling fan) is proportional to the CFM that a ceiling fan can produce. Adequate ceiling fan sizing simply means figuring out how many CFM ceiling fans you need. An easy (albeit less accurate) way to size a ceiling fan is to check the diameter of the ceiling fan blades and the square footage of the room.

The ceiling fan size guide below includes both the size of the room (in square feet and width × length), the appropriate ceiling fan blade size for such rooms, as well as estimated CFM airflow output.

*pay attention:* This size guide is valid for **standard 8 feet ceiling height**, Below the chart, we explain how to size a ceiling fan for heights over 8 feet. We also explain how to measure ceiling fan sizes for an odd number of blades (3-blade, 5-blade fans) and an even number of blades (4-blade, 6-blade fans).

On top of that, we also see **2 real life examples** (Average bedroom and 10×10 room) How to measure ceiling fan size and estimate how many square feet of room such a fan can adequately cover:

## Ceiling Fan Size Guide

room size: |
Dimensions: |
Blade Size: |
Sufficient CFM: |
Room example: |

50 sq. ft. less than |
6×6, 6×8 Rooms | 29 inches or less | 1000-2500 CFM | small bathroom |

50 to 75 square feet |
8×8, 10×6 Rooms | 29 to 36 inches | 1200-2800 CFM | small room |

75 to 100 square feet |
8×10, 10×10 Rooms | 36 to 38 inches | 1500-3500 CFM | standard bathroom |

100 to 150 square feet |
10×12, 12×12 Rooms | 38 to 42 inches | 2000-4000 CFM | standard room |

150 to 200 square feet |
12×14, 14×14 Rooms | 42 by 46 inches | 2500-4500 CFM | big bathroom |

200 to 300 square feet |
15×15, 16×16 Rooms | 46 by 52 inches | 3000-5000 CFM | big room |

300 to 400 square feet |
18×18, 20×20 Rooms | 52 to 54 inches | 4000-6000 CFM | small room |

400 to 500 square feet |
20×22, 22×22 Rooms | 54 by 56 inches | 5000-7000 CFM | 2 rooms |

500 to 750 square feet |
24×24, 25×25, 26×26 Rooms | 56 to 70 inches | 6500-9000 CFM | 3 rooms |

750 to 1,000 square feet |
28×28, 30×30 Rooms | 70 by 84 inches | 8500-12000 CFM | 4 rooms |

1,000 square feet or more |
32×32, 34×34 Rooms | 84 inches or more | 10,000+ CFM | 4+ rooms |

This ceiling fan size chart is pretty self-explanatory. Large rooms will require ceiling fans with longer blades that can generate higher airflow.

*Example:* Suppose you have a 14×14 bedroom and you want to know what size ceiling fan you need for such a bedroom. Look at the ceiling fan size chart above, look at the 150-200 square foot size (14×14 by 196 sq ft), and you can see that you’ll need a 46-inch ceiling fan with about 4000 cfm of airflow.

Now, if you already have a fan or are buying a fan for a certain room, you need to know how to measure ceiling fan size.

Let’s see how we can measure the size of the fan blades:

## How to measure ceiling fan size? (diameter of blade)

We talk about 36-inch, 42-inch, 52-inch ceiling fans etc. In short, it is shaped like a ceiling fan. When sizing a ceiling fan it is quite useful to know how to measure ceiling fan size.

*pay attention:* Did you know that the rotating blades have different directions in winter versus summer? You can check the correct clockwise vs counterclockwise direction for both the seasons here.

Namely, we are measuring the span of the blade. There are two ways to measure the size of a ceiling fan, depending on whether the fan has an even number of blades or an odd number of blades:

**even number of blades**ceiling fans. these*4-blade or 6-blade fan*,**odd number of blades**ceiling fans. these*3-blade or 5-blade fan*,

It is easy to measure blade length with the number of blade wings. Let’s start with even, and we’ll show how to do it for odd after that.

Here’s how to measure ceiling fan size for an even number of blades:

- Turn off the fan before measuring.
- Use a ladder to access the ceiling fan, or break it apart for easy measurement.
- Use a measuring tape. With the same blade fan, stretch the measuring tape
**from the tip of one blade to the tip of the blade opposite the first blade**, - Label the measured ceiling size.

The process is very similar for odd numbers of blades, with significant differences in the third and fourth steps:

- Turn off the fan before measuring.
- Use a ladder to access the ceiling fan, or break it apart for easy measurement.
- Use a measuring tape. With a fan with odd blades, pull the measuring tape off
**The tip of a blade in the center of a ceiling fan**, You are measuring the radius of the fan. - Use the measured radius of the fan and
**2 it. multiply by**, The result is the diameter of the fan blades; Ceiling fan size. - Label the measured ceiling size.

Here’s an example for an odd-numbered fan: Let’s say you have a 3-blade fan and you want to measure the size of the fan. As in the third step, you measure from the tip of the blade to the center and get the result: 21 inches. This is the radius. Here’s how to get the full size of an odd-numbered blade ceiling fan:

**ceiling fan size** = 21 inches × 2 = **42-inch fan**

If you look at the ceiling fan sizing chart above, you can see that a 42-inch fan is the appropriate size to provide ventilation in rooms of 150-200 square feet.

If you have high ceilings then you need to increase the size of the roof a little. Let’s take a look at how to size a ceiling fan for rooms with high ceilings:

### Rooms with high ceilings (you’ll need a bigger fan)

Any ceiling fan should provide adequate ventilation in a room. We primarily base ceiling fan sizes on square footage. What we shouldn’t miss, however, is rooms that have ceiling heights higher than the standard 8 feet.

A ceiling fan ventilates the air in the room. Higher ceilings equal more air, and so you’ll need a bigger fan in rooms with higher ceilings. This is to maintain the recommended ACH (air changes per hour) air flow.

Every foot of height above 8 feet will raise the ceiling fan **CFM requirement up to 12.5%**, Here’s how much more airflow will be needed in rooms with high ceilings:

- Standard 8 ft ceiling height.
*Example: 2,000 cfm.* - A ceiling height of 9 feet needs 12.5% more airflow.
*Example: 2,250 cfm.* - A ceiling height of 10 feet requires 25% more airflow.
*Example: 2,500 cfm.* - A ceiling height of 11 feet requires 37.5% more airflow.
*Example: 2,750 cfm.* - A ceiling height of 12 feet requires 50% more airflow.
*Example: 3,000 cfm.* - A ceiling height of 13 feet requires 62.5% more airflow.
*Example: 3,250 cfm.* - A ceiling height of 14 feet requires 75% more airflow.
*Example: 3,500 cfm.*

It is easier to calculate CFM than the actual ceiling fan blade span. To accurately determine ceiling fan size, you can check the CFM airflow output in the chart above.

In practice, this would mean that for a 12×12 room with 14 feet of ceilings, a 42-inch fan would not be sufficient. You should opt for 46 inch or even 48 inch fan for extra air in the room due to high ceiling.

Let’s tackle two examples of how to correctly size a ceiling fan:

#### ceiling fan size for bedroom (example 1)

The size of an average bedroom in the US is 14×16 feet or 224 square feet. What size ceiling fan do you need for such a bedroom?

If you have a ceiling height of 8 feet, you can simply refer to the ceiling fan size guide for the size of an upstairs bedroom. You can see that for a 200-300 sq ft bedroom, you need a 46-52 inch bedroom fan (generating 3000-5000 cfm airflow)

Since 224 square feet is closer to the 200 square foot mark, you’ll most likely need a 48-inch fan for the average bathroom. Such a fan will generate around 3500 cfm of airflow and adequately ventilate your bedroom.

If you have ceilings higher than 8 feet, you’ll need a bigger fan for the bedroom. You add 12.5% for each additional foot of height, and your options will be between 52-56-inch bedroom ceiling fans.

#### Ceiling fan size for a 10×10 room (Example 2)

10×10 is one of the most common room sizes. This is basically a 100 square foot room. What size ceiling fan do you need for a 10×10 room?

You just check the chart above. A 36-inch or 38-inch fan is needed in rooms of 75-100 square feet. Since 100 square feet is the upper limit here, you’ll obviously need a 38-inch ceiling fan for a 10×10 room.

That’s when you have a standard ceiling height of 8 feet. With higher ceilings, you’re looking at 42-46-inch fans; Those high flow ceiling fans will be enough to ventilate 10×10 rooms with high ceilings.

Hopefully, this shows you how you go from choosing a ceiling fan size.

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