1. What is a Well Pump Flow Rate Calculator?

Definition: This calculator estimates the flow rate of a well pump in gallons per minute (GPM) based on pump horsepower, efficiency, and total dynamic head.

Purpose: It helps well owners, plumbers, and engineers determine the expected water delivery rate of a pump system.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( HP \) — Pump horsepower
• \( \eta \) — Pump efficiency (0-1, typically 0.7-0.85)
• \( H \) — Total dynamic head (feet)

Explanation: The formula converts mechanical power to hydraulic power, accounting for pump efficiency and the work needed to lift water against gravity.

3. Importance of Flow Rate Calculation

Details: Proper flow rate estimation ensures adequate water supply, proper pump sizing, and efficient system operation.

4. Using the Calculator

Tips: Enter the pump horsepower, efficiency (default 0.8), and total dynamic head in feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: It's the total equivalent height the pump must overcome, including vertical lift and friction losses in pipes.

Q2: What's a typical pump efficiency?
A: Most submersible pumps have 70-85% efficiency (0.7-0.85). The default of 0.8 represents a good average.

Q3: What flow rate is needed for a house?
A: Typical residential needs range from 5-20 GPM, depending on the number of fixtures and simultaneous uses.

Q4: How do I find my pump's horsepower?
A: Check the pump's nameplate or manufacturer specifications. Common residential pumps are 0.5-1.5 HP.

Q5: Does this account for pipe size restrictions?
A: No, the head value should include friction losses from pipe size and length in your system.