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 head.

Purpose: It helps determine the water delivery capacity of a well pump system for residential, agricultural, or industrial applications.

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 (decimal between 0 and 1)
• \( H \) — 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, correct pump sizing, and efficient system operation.

4. Using the Calculator

Tips: Enter the pump horsepower, efficiency (default 0.85 for 85%), and total head in feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

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

Q2: What's a typical pump efficiency?
A: Submersible pumps typically range 70-85% (0.7-0.85), while jet pumps are often 50-70% efficient.

Q3: Why is 3960 in the formula?
A: This is a conversion factor that relates horsepower to foot-pounds per minute (1 HP = 3960 ft-lb/min).

Q4: What's the 8.34 factor?
A: This is the weight of one gallon of water in pounds at standard conditions.

Q5: How do I measure total head?
A: Measure vertical distance from water level to discharge point, plus account for pipe friction losses (typically add 10-20%).