How to Calculate CFM from FPS

The FPS to CFM Calculator converts air velocity in feet per second (FPS) to cubic feet per minute (CFM) based on the cross-sectional area. The formula is:

Where:

• \( CFM \): Cubic feet per minute (airflow rate).
• \( FPS \): Air velocity in feet per second (1 FPS = 60 FPM).
• \( Area \): Cross-sectional area, converted to square feet (e.g., 1 sq ft, 1/144 sq in, 1/929.0304 sq cm, 10.7639 sq m, 9 sq yd).

Enter the air velocity (FPS), area, and select the area unit to calculate the CFM.

Using the FPS to CFM Calculator

This calculator is useful for HVAC and ventilation system design to determine airflow rates.

Input the air velocity in feet per second (FPS), the area, and select the area unit. The calculator converts FPS to FPM (1 FPS = 60 FPM) and outputs the airflow in cubic feet per minute (CFM).

Example: For an air velocity of 8.33 FPS and an area of 288 sq in.

1. Air Velocity: \( 8.33 \, \text{FPS} = 500 \, \text{FPM} \) (since 1 FPS = 60 FPM)
2. Area: \( 288 \, \text{sq in} = 2 \, \text{sq ft} \) (since 1 sq ft = 144 sq in)
3. Calculation: \( CFM = 500 \times 2 = 1000 \, \text{CFM} \)
4. Result: \( 1000 \, \text{CFM} \)

Use this tool for airflow calculations in duct systems.

Common FAQ

Below are frequently asked questions about FPS to CFM calculations:

• Q: What is FPS?
  A: FPS stands for feet per second, measuring air velocity.
• Q: What is CFM?
  A: CFM stands for cubic feet per minute, measuring airflow volume.
• Q: How is FPS converted to FPM?
  A: 1 FPS = 60 FPM, as per the given conversion factor.
• Q: Can negative values be used?
  A: No, FPS and area must be positive; invalid inputs leave the result blank.
• Q: What if the area is irregular?
  A: Use the average cross-sectional area of the duct in the selected unit.