Submersible Well Pump Size Calculator: Find the Right GPM & Horsepower
Calculate the appropriate submersible well pump size by entering your well specifications and water usage requirements below. This calculator helps determine the correct pump capacity in GPM (Gallons Per Minute) and horsepower based on well depth, water level, and household water needs.
List of the Best Submersible Well Pump:
Understanding Submersible Well Pump Sizing
Proper submersible pump sizing is critical for efficient water delivery and system longevity. An accurately sized pump ensures adequate water pressure, minimizes energy consumption, and prevents premature wear while meeting your household's water demands.
Key Factors in Submersible Pump Sizing
| Factor | Description | Impact on Sizing |
|---|---|---|
| Total Dynamic Head (TDH) | Sum of vertical lift, pressure head, and friction loss | Primary determinant of required horsepower |
| Peak Demand | Maximum simultaneous water usage | Determines required GPM capacity |
| Well Characteristics | Depth, static water level, and well yield | Affects pump type and placement |
| Pressure Requirements | Desired system pressure | Affects horsepower needs |
Submersible Pump Capacity Guidelines
| Household Size | Recommended GPM | Typical HP Range | Pressure Tank Size |
|---|---|---|---|
| 1-2 People | 5-8 GPM | 0.5-0.75 HP | 20-30 gallon |
| 3-4 People | 8-12 GPM | 0.75-1.0 HP | 30-44 gallon |
| 5-6 People | 12-16 GPM | 1.0-1.5 HP | 44-82 gallon |
| 7+ People | 16-20 GPM | 1.5-2.0 HP | 80+ gallon |
Total Dynamic Head Calculation
| Component | Calculation | Example |
|---|---|---|
| Vertical Lift | Pump depth to surface | 150 ft |
| Pressure Head | PSI × 2.31 | 50 PSI = 115.5 ft |
| Friction Loss | Based on pipe size/flow | 15 ft |
| Elevation | Height to highest fixture | 20 ft |
| Total TDH | Sum of all components | 300.5 ft |
Frequently Asked Questions
How deep can a submersible well pump work?
Standard submersible pumps can operate to depths of: - 1/2 HP: Up to 200 ft - 3/4 HP: Up to 250 ft - 1 HP: Up to 300 ft - 1.5+ HP: 400-600 ft Deep well models can exceed 700 ft with multiple stages
What's the difference between 2-wire and 3-wire submersible pumps?
Key differences: - 2-wire: Simpler installation, control box built into motor - 3-wire: Separate control box, easier to service - 3-wire: Better for higher HP applications - 2-wire: Fewer components to fail
How long should a submersible pump run each cycle?
Ideal runtime: - Minimum 1-2 minutes per cycle - Avoid short cycling (<30 seconds) - 5-10 minute runtimes are optimal - Cycle 10-20 times per day maximum
What size pressure tank do I need?
Tank sizing guidelines: - Minimum 1 gallon per GPM of pump capacity - 20-30 gallon for typical residential systems - Larger tanks reduce pump cycling - Consider "drawdown" capacity, not total volume
How do I protect my submersible pump?
Essential protection: - Proper overload protection - Low water cutoff switch - Lightning/surge protection - Check valve to prevent backspin - Regular well maintenance
What voltage should I use for my submersible pump?
Voltage selection: - 1/2-1 HP: Typically 115V or 230V - 1.5+ HP: Usually 230V - 5+ HP: May require 460V - Consider voltage drop for long wire runs
How often should a submersible pump cycle?
Healthy cycling: - 10-20 cycles per day maximum - Fewer cycles = longer pump life - More than 30 cycles/day indicates undersized tank - Monitor for increasing frequency (sign of problems)
What's the lifespan of a submersible pump?
Typical lifespan: - 8-15 years with proper installation - 15-25 years in ideal conditions - Reduced by sand, cycling, power surges - Quality brands often outlast cheaper models
Can I install a submersible pump myself?
Installation considerations: - Professional installation recommended - Special tools required (torque arrestor, etc.) - Critical to get wiring and piping correct - Mistakes can be costly to repair - Some states require licensed installers
How do I know if my pump is failing?
Warning signs: - Decreasing water pressure - Increased cycling frequency - Dirty or sandy water - Higher electricity usage - Unusual noises from well
Installation Best Practices
- Install torque arrestor to prevent pipe damage
- Use stainless steel clamps and proper cable guards
- Ensure proper well seal at casing
- Install check valve above pump (additional at surface optional)
- Use proper wire sizing for voltage drop
Maintenance Recommendations
- Annual water quality testing
- Monitor pressure gauge readings
- Listen for changes in pump operation
- Check electrical connections periodically
- Keep well records and service history
Troubleshooting Common Issues
- No water: Check power, pressure switch, breakers
- Low pressure: Check for clogged pipes or failing pump
- Short cycling: Likely pressure tank issue
- Sand in water: May indicate well or pump problems
- High electric bill: Could signal pump working too hard