1. What is Water Flow Rate Calculation?

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

Purpose: It helps engineers, plumbers, and irrigation specialists design and analyze water systems.

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 (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 Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper system design, prevent pipe overpressure, and help maintain efficient water distribution.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why 448.83 as the conversion factor?
A: It combines 7.48052 (gallons per cubic foot) and 60 (seconds per minute): 7.48052 × 60 ≈ 448.83.

Q2: What's a typical water velocity in pipes?
A: Residential systems typically use 4-8 ft/s, while industrial systems may go higher.

Q3: How do I calculate pipe cross-sectional area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q4: Does this work for other liquids?
A: Yes, but the conversion factor changes based on liquid density (use 448.83 only for water).

Q5: What if my area is in inches?
A: Convert to square feet first (divide square inches by 144).