1. What is the GPM Formula?

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

Purpose: It helps engineers, plumbers, and fluid system designers calculate flow rates in piping systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( V \) — Fluid velocity (feet per second)
• \( A \) — Cross-sectional area (square feet)
• 448.83 — Conversion factor (cubic feet to gallons and seconds to minutes)

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

3. Importance of GPM Calculations

Details: Accurate GPM calculations ensure proper pipe sizing, pump selection, and system performance in hydraulic systems.

4. Using the Calculator

Tips: Enter the fluid velocity in ft/s and pipe cross-sectional area in ft². For circular pipes, area = π × (diameter/2)².

5. Frequently Asked Questions (FAQ)

Q1: What's a typical velocity for water in pipes?
A: Residential plumbing: 4-8 ft/s, industrial systems: 5-10 ft/s, depending on application.

Q2: How do I calculate pipe area?
A: For circular pipes: Area = π × r² (where r is radius in feet).

Q3: Why 448.83 conversion factor?
A: It combines 7.48052 (gallons per cubic foot) × 60 (seconds to minutes) = 448.8312.

Q4: Can I use this for other liquids?
A: Yes, but the velocity should be appropriate for the specific fluid's viscosity and system requirements.

Q5: What if I know diameter instead of area?
A: First calculate area: A = π × (diameter/2)², then use this calculator.