1. What is Water Flow Rate Calculator?

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

Purpose: It helps engineers, plumbers, and irrigation specialists determine water flow in pipes and channels.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The velocity multiplied by area gives flow in cubic feet per second, which is then converted to GPM.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper pipe sizing, pump selection, and system performance in plumbing and irrigation systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's a typical water velocity in pipes?
A: Residential plumbing typically uses 4-8 ft/s, while irrigation systems may use 5-10 ft/s.

Q2: How do I calculate cross-sectional area?
A: For circular pipes: \( A = \pi \times r² \) where r is the radius in feet.

Q3: Why 448.83 as the conversion factor?
A: It combines 7.48052 (gallons per cubic foot) and 60 (seconds per minute).

Q4: Does this work for any liquid?
A: Yes, but the result will be in GPM of that liquid (density doesn't affect volume flow rate).

Q5: What's a good flow rate for household water?
A: Typical homes need 5-12 GPM, with higher rates for multiple fixtures.