TECH TIPS

HOW COMPUTER CASE FANS ARE MEASURED

1) DIMENSIONS

Standard PC case fans are square in shape. 

They are measured from edge-to-edge. I.E. an 80mm fan will measure exactly 80mm from end to end.

80MM

80MM

2) FAN SPEED

Fan speed is measured in rounds per minute (RPM).

How fast the blades spin per minute. Not really a useful spec.

3) AIR FLOW

Measured in cubic feet per minute (CFM).

A higher number means more air getting moved.

PC fans generally move about 20 to 70 CFM.

4) NOISE

Generally measured in decibels relative to air (dBA). 

25dBA is a quiet library, and PC fans are generally around 20 to 30 dBA.

5) POWER

Standard PC case fans run on 12V.

.But there are also USB 5~12V fans.