1. What Is the Flow Rate Formula?

Definition: This calculator computes the volumetric flow rate in gallons per minute (GPM) based on fluid velocity and cross-sectional area.

Purpose: It helps engineers, plumbers, and fluid system designers determine flow rates in pipes and channels.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( V \) — Velocity (feet per second)
• \( A \) — Cross-sectional area (square feet)
• 448.83 — Conversion factor (ft³/s to GPM)

Explanation: The formula converts the basic volumetric flow rate (V × A) from cubic feet per second to gallons per minute.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper system design, pump sizing, and compliance with engineering standards.

4. Using the Calculator

Tips: Enter the fluid velocity in ft/s and the pipe/channel cross-sectional area in ft². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 448.83?
A: It converts cubic feet per second (1 ft³/s = 448.83 gallons per minute).

Q2: How do I find the cross-sectional area?
A: For circular pipes: A = π × (diameter/2)². For rectangular channels: A = width × height.

Q3: What's a typical velocity for water in pipes?
A: Typically 2-5 ft/s for residential plumbing, 5-10 ft/s for industrial applications.

Q4: Can I use this for gases?
A: This formula works for incompressible fluids. For gases, additional factors like compressibility must be considered.

Q5: How accurate is this calculation?
A: It provides theoretical flow rate. Actual flow may vary due to friction, viscosity, and pipe roughness.