How to Determine Ceiling Fan Blade Sweep

Ceiling fan blade sweep refers to the distance around the circle the blades create as they turn. Knowing this number can prevent accidents from occurring by installing a ceiling fan too close to tall appliances or shelves. Knowing the ceiling fan blade sweep will also help you to choose a new fan or replace the blades on an existing fan. A correctly sized fan will efficiently cool your space.

Step 1

Measure from the center of the fan to the tip of one of the blades. Write this number down as the radius of the blade sweep.

Step 2

Multiply the radius by 2 to determine the diameter. For instance a radius of 10 inches x 2 = 20 inches in diameter.

Step 3

Multiply the diameter by 3.14 (pi) to determine the ceiling fan blade sweep. In the example: 20 inches x 3.14 = 62.8 inches.

Step 4

Choose a replacement fan by measuring the size of your room and matching the fan blade sweep to the area of the room.

Step 5

Measure the length and width of the room in feet, and multiply them together. For instance a 10x15-foot room would have an area of 10 feet x 15 feet = 150 square feet.

Step 6

Estimate a fan blade sweep of 42 inches for rooms up to 144 square feet; a 44-inch fan for rooms between 144 and 225 square feet; a 52-inch blade sweep for rooms up to 400 square feet. Consider installing more than one fan for larger spaces.