Enter the cubic feet per minute (Cfm) and the power in watts into the calculator to determine the Cfm per watt.

Cfm Per Watt Calculator

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Cfm Per Watt Formula

The following formula is used to calculate the Cfm per watt for a given power and airflow.

Cfm/W = Cfm / W

Variables:

  • Cfm/W is the cubic feet per minute per watt
  • Cfm is the cubic feet per minute of airflow
  • W is the power in watts

To calculate the Cfm per watt, divide the cubic feet per minute of airflow by the power in watts. This will give you the efficiency of the airflow in terms of power consumption.

What is Cfm Per Watt?

Cfm per watt is a measure of the efficiency of a fan or other airflow device. It indicates how much airflow (in cubic feet per minute) is produced for each watt of power consumed. A higher Cfm per watt value means that the device is more efficient, providing more airflow for less power. This metric is important in applications where energy efficiency is a priority, such as in HVAC systems, ventilation, and cooling systems.

How to Calculate Cfm Per Watt?

The following steps outline how to calculate the Cfm per watt.


  1. First, determine the cubic feet per minute (Cfm) of airflow.
  2. Next, determine the power consumption in watts (W).
  3. Finally, calculate the Cfm per watt using the formula Cfm/W = Cfm / W.
  4. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Cubic Feet per Minute (Cfm) = 500

Power Consumption (W) = 50