Motor horsepower from total dynamic head, plus drop pipe, cable, pitless adapter, tank and cost.
Estimates are planning aids, not a professional quote. Double-check quantities and product coverage — and any local code or permit requirements — before you buy.
⚠ This is a planning estimate for a new pump and pitless install, not a substitute for your well driller's log. Confirm actual well depth, static water level and casing diameter from that log or a fresh sounding before ordering pipe, cable and the pump itself — guessing any of the three throws off everything downstream of it.
| Plumbing & Heating | $1,257–$1,701 |
| Electrical | $261–$354 |
| Total | $1,519–$2,055 |
Excludes tools, delivery, tax and permit fees. Labor not included — this is a DIY materials estimate.
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About this calculator
The Well Pump Builder sizes the pump itself from real hydraulics, not just a parts list — enter your well depth, the static water level, how much water the house needs at once, and your pressure switch setting, and it works out total dynamic head from where the pump actually sits, friction loss over the drop line, and the head equivalent of your tank's cutout pressure, then picks the smallest motor that clears it.
From there it prices the drop pipe or poly line, submersible cable sized to hold voltage drop over the full run, the pitless adapter and well seal for your casing size, torque arrestor, check valves, a bladder tank sized to real drawdown at your pressure setting, and the dedicated 230V circuit to run it. This covers a new submersible pump and pitless install, not a like-for-like pump swap — if you're only replacing a failed unit in an existing setup, most of the pipe and pitless lines below won't apply.
Step by step
A step-by-step walkthrough to go with your plan above. Follow the product instructions and any local code or permit requirements as you work.
Pull the driller's log for actual depth, static water level and casing diameter, or have a fresh sounding taken — every downstream figure in this calculator depends on getting these three right rather than guessed.
Enter depth, static level, demand and pressure setpoint to get motor horsepower, cable gauge, drop pipe and tank size, then order everything before you break ground at the wellhead.
Excavate around the casing below frost depth, install the pitless adapter, and dry-fit the drop pipe run to confirm your calculated length before committing any glue or clamps.
Splice the pump's motor leads to the submersible cable with the heat-shrink kit, tie on the safety rope, and lower the assembly on the drop pipe using a hoist or tripod winch — never on the cable or rope alone.
Wire the control box if your motor needs one, land the dedicated 230V circuit on its own breaker sized to the motor's full-load current, and have a licensed electrician make the panel connection.
Install the bladder tank at its correct precharge pressure (set equal to the switch's cut-in point) and wire the pressure switch to your chosen setpoint.
Trench the horizontal run to the house below frost depth, lay in the supply line and cable together, and backfill once you've confirmed there are no leaks at the pitless connection.
Open the system to charge the tank, then run water at your rated demand and confirm the pump doesn't short-cycle — it should run for its full minimum cycle time before the pressure switch cuts it off.
Equip the job
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Interior & Finishing
Answers
Motor horsepower isn't set by depth alone — it's flow (GPM) against total dynamic head, the sum of the vertical lift from where the pump sits, friction loss over the drop and supply line, and the head equivalent of your pressure tank's cutout pressure. A pump rated for 10 GPM at zero head might need a full size larger once it's lifting from 150 ft and pushing against a 50 psi cutout. This calculator sizes from all three terms together and picks the smallest standard motor that still clears your actual head, which is the number that matters, not depth by itself.
Static water level is where the water table sits at rest — the moment the pump starts drawing, that level drops, and if the pump isn't submerged well below where it settles under load, it sucks air and burns out. This calculator sets the pump at least 20 ft below static level for that margin, or 15 ft off the bottom of the well to stay clear of sediment, whichever puts it deeper. If your well's yield is marginal for your demand, get your driller to confirm the actual safe pumping level before finalizing pump depth.
It depends on the motor's wiring, not just its horsepower. Smaller residential submersible motors, typically 1/2 and 3/4 HP, are commonly built as 3-wire designs that need a separate control box holding the start capacitor and relay outside the well. Most 1 HP and larger single-phase motors in this lineup are 2-wire, with those components built into the motor itself, so they skip the box entirely. Check your specific pump's spec sheet — 2-wire and 3-wire versions exist at overlapping horsepowers from different manufacturers.
From two things together: how many gallons the pump needs to deliver during its shortest allowed run (bigger motors need a longer minimum run time to avoid overheating from frequent starts), and how much of the tank's total volume is actually usable at your pressure setting. A bladder tank's usable drawdown shrinks as the pressure swing narrows — the same tank yields less at 40/60 psi than at 30/50 — so this calculator computes real drawdown from your setpoint rather than assuming a fixed fraction, then picks the smallest standard tank size that covers the required run time.
Poly (SDR21 polyethylene) comes in continuous coils, so a deep well needs no field joints below the pitless adapter, and it flexes rather than cracking if the ground shifts — the common default for most residential installs. Schedule 80 PVC is rigid, sold in 20 ft sticks glued together at every joint, and is preferred in some areas by code or for pumps that need a rigid column for torque control. Poly is generally the faster, cheaper install; PVC costs a bit more in fittings and labor for the added joints.
Parts of it are within reach for an experienced DIYer — running the electrical to a control box, connecting the pressure tank and switch, and backfilling the trench. But pulling and setting the pump itself takes a hoist or tripod winch capable of controlled lowering on the drop pipe and safety rope, splicing waterproof connections at depth, and in many areas a permit and licensed electrician for the panel connection. Deep or large-diameter wells in particular are routinely professional work — line up a well contractor or electrician for those pieces even on an otherwise DIY job.