Instantly calculate Motor HP & Stages with this borewell pump capacity calculator. Accurate estimation for V4 (Domestic) & V6 (Agriculture) pumps based on depth.
Introduction
Are you struggling to select the right submersible pump for your new borewell? A common question we get is: “I have drilled an 800-foot borewell; how much HP and which Stage motor should I select?”
Choosing the wrong pump can lead to motor burnout, low water pressure, or high electricity bills. You don’t need to guess anymore. Use our Advanced Borewell Pump Calculator below to get an instant estimation based on your depth and water requirements.
100mm Borewell Pump Specification Calculator
Understanding Your Results
1. Why “Total Head” is More Than Just Depth
Many people make the mistake of calculating pump power based only on the depth of the drilled hole. However, to get accurate water discharge, we must calculate the Total Dynamic Head (TDH). This includes:
- Vertical Depth: The actual distance from ground level to where the pump is submerged inside the well.
- Above-Ground Lift: The vertical height the water must travel after reaching the surface to fill your overhead storage tank.
- Friction Loss: As water travels through the pipe, it loses pressure due to resistance against the pipe walls, elbow joints, and horizontal runs.
- Drawdown: The temporary drop in the water level inside the well once the pump actively starts running.
Our calculator automatically adds a standard 6% safety margin (Head Friction Factor) to ensure your recommended configuration pushes water all the way to your tank with solid pressure.
2. Matching Pump Performance to Water Yield
A pump shouldn’t just match the depth of your well; it must match the recovery rate (yield) of your water source.
- Low Yield (< 2 Inches): Requires a low-discharge radial flow configuration. Using a high-flow pump in a low-yield well will drain the water column faster than it recharges, causing the pump to run dry and risk motor burnout.
- High Yield (> 3 Inches): Can safely handle high-capacity, wider delivery configurations to maximize water flow per hour.
3. What are “Stages” in a Submersible Pump?
If the calculator recommends a “32 Stage” or “52 Stage” pump, it refers to the number of individual impellers (spinning blades) stacked inside the pump unit.
- 1 Stage (Impeller): Lifts water by a specific height margin depending on the hydraulic design.
- More Stages = Higher Pressure: Stacked impellers don’t increase the volume of water; they increase the pressure. For deep wells, you need more stages to push the water column vertically against gravity.
4. The 10% Bottom Safety Buffer Rule
You will notice that the calculator automatically recommends placing the pump exactly 10% higher than the absolute bottom of your well (e.g., at 630 feet for a 700-foot borewell).
Protects Against Seasonal Water Drops: During peak summer, local water tables plunge significantly. A strict 10% safety cushion ensures the motor stays safely immersed in deep water, preventing dry-run overheating and premature coil burnout.
Prevents Silt Accumulation: Borewells collect muddy silt and small stones at the very bottom over time. Placing the pump right at the bottom floor can cause it to suck in debris, blocking the impellers and causing a mechanical lock-up.
Frequently Asked Questions (FAQs)
Q: What is a 100mm pump series?
A: A 100mm pump (commonly called a V4 or 4-inch pump) has a maximum outer diameter of 97mm to 98mm. It is mechanically engineered to slide comfortably into standard 4-inch or larger borewell casing pipes.
Q: How much HP motor is required for an 800-foot borewell?
A: For a standard residential setup delivering a reliable water supply, an 800-foot deep well typically requires a 4.0 HP to 5.0 HP motor paired with approximately 45 to 55 stages, depending entirely on where your stable static water level sits.
Q: Does this calculator work for Openwell pumps?
A: No. This tool is explicitly designed using technical catalog curves for Borewell Submersible Pumps that operate fully submerged in narrow, deep-drilled wells.
Q: Can I use a 5 HP pump if my borewell only yields 1.5 inches of water?
A: It is highly discouraged. A 5 HP pump pushes a higher volume of water. If your water source cannot replenish itself fast enough, the pump will frequently run out of water, trigger dry-run faults, or overheat the motor. Always choose a lower-discharge model optimized for low-yielding sources.
Q: Why does the calculator show a lower depth that is shorter than my total borewell depth?
A: To protect your investment! Keeping the pump roughly 10% clear of the absolute bottom protects it from swallowing accumulating mud and silt, while maximizing the amount of water sitting above the pump to act as a cooling shield for the motor.