Well Pump Sizing Calculator

A well pump must lift water the entire way - from the static level, through the drawdown, up to the tank, against the tank pressure and past pipe friction. All of that stacks into one number: total dynamic head.

Well Pump Sizing Calculator combines your demand flow with well depth, elevation, pressure and pipe losses to estimate the pump capacity in GPM and horsepower.

• Flow demand: Enter peak GPM directly.
• Depth & drawdown: Static level plus pumping drop.
• Elevation & pressure: Lift to tank and cut-in pressure.
• Friction: Optional pipe loss allowance.
• HP estimate: Motor size from the pump curve math.
• Export: Text, CSV or JSON report.

1. Enter peak flow demand (GPM).
2. Add well depth, static level and drawdown.
3. Set elevation, pressure and friction.
4. Read the total dynamic head and horsepower.
5. Export the result for the pump curve match.

Example 1. A 100 ft well with a 40 ft static level, 10 ft drawdown, 15 ft elevation rise, 40 psi cut-in and 20 ft friction at 10 GPM sums to roughly 165 ft TDH.

Example 2. Doubling the depth to 200 ft adds the static lift straight to head - same house demand needs roughly 65 ft more TDH and a larger motor.

• One head number: Depth to pressure, all summed.
• Real hydraulics: Drawdown and friction included.
• HP answer: Preliminary motor size fast.
• Curve-ready: GPM + TDH to match a pump curve.
• Free and private: No uploads, no logging.