Fan Calculator (CFM)

Enter the power output and pressure of your fan to calculate the CFM (cubic feet per min). The CFM is the volume per minute of air or fluid a fan is pushing.

Fan CFM Formula

The following formula can be used to calculate the volumetric flow rate of air by a fan. This formula assumes an efficiency of 100%.

CFM = P*2122/p

  • Where CFM is the cubic feet per minute
  • P is the power output (Watts)
  • p is the pressure (pascals)

In reality, the flow rate of a fan will vary based on the size, shape, and performance of the motors. No fan will ever reach a 100% efficiency, but this calculator assumes as much for simplifying the equation. To calculate the results of a real fan, simply multiply the result by the efficiency.

fan calculator