Deep Well Submersible Pump Sizing Calculator
Calculate well Total Dynamic Head (TDH), submersible pump horsepower (1/2, 3/4, 1, 1.5 HP), GPM flow rate, and pressure tank drawdown size.
Calculated Results
Frequently Asked Questions
What is Total Dynamic Head (TDH) in a water well?
Total Dynamic Head (TDH) is the total equivalent vertical height a pump must lift water. It combines: (1) Depth to pumping water level, (2) Vertical elevation rise to the pressure tank, (3) Friction head loss through pipes and elbows, and (4) Pressure tank head (Cut-out PSI × 2.31 feet/PSI).
What size well pump is needed for an average home?
Most single-family homes with 2 to 3.5 bathrooms require a 10 GPM flow rate. Depending on well depth: 1/2 HP handles shallow wells under 100 ft; 3/4 HP handles 100 to 250 ft; 1 HP to 1.5 HP handles deep wells 250 to 450+ ft.
Why is pressure tank drawdown size critical for pump longevity?
Submersible well pump motors are cooled by water rushing past the motor sleeve. Rapid cycling (short-cycling) causes motor overheating and capacitor failure. The pressure tank must store enough drawdown gallons so the pump runs continuously for at least 60 seconds per cycle.
How does pressure in PSI convert to feet of water head?
1 PSI of water pressure equals exactly 2.31 feet of vertical water head. Conversely, a 2.31-foot column of water exerts 1.0 PSI of hydrostatic pressure at its base.