GPM to HP Calculator: Convert Flow Rate to Horsepower
Calculate the required horsepower (HP) for a pump based on the flow rate in gallons per minute (GPM) and pressure in feet of head. This calculator helps you determine the power needed for efficient pump operation.
Understanding GPM to HP Conversion
Converting gallons per minute (GPM) to horsepower (HP) is essential for determining the power required to operate a pump efficiently. This calculation helps in selecting the right pump for your application.
Key Factors in GPM to HP Calculation
Several factors influence the horsepower required for a pump:
| Factor | Description | Impact on HP |
|---|---|---|
| Flow Rate (GPM) | Volume of liquid moved per minute | Higher flow rates require more HP |
| Pressure (ft of head) | Total dynamic head the pump must overcome | Higher pressure increases HP demand |
| Pump Efficiency | Percentage of input power converted to useful work | Lower efficiency requires more HP |
Formula for GPM to HP Conversion
The formula to calculate horsepower (HP) from GPM is:
HP = (GPM × Pressure) / (3960 × Efficiency)
Where:
- GPM: Flow rate in gallons per minute
- Pressure: Total dynamic head in feet
- Efficiency: Pump efficiency as a percentage (e.g., 75% = 0.75)
Common Applications
| Application | Typical GPM Range | Typical HP Range |
|---|---|---|
| Residential Water Supply | 5-20 GPM | 0.5-2 HP |
| Irrigation Systems | 10-50 GPM | 1-5 HP |
| Industrial Processes | 50-500 GPM | 5-50 HP |
| Fire Protection | 100-1000 GPM | 10-100 HP |
Frequently Asked Questions
What is the relationship between GPM and HP?
GPM (gallons per minute) measures flow rate, while HP (horsepower) measures power. The relationship depends on pressure and pump efficiency.
How does pump efficiency affect HP?
Lower efficiency pumps require more horsepower to achieve the same flow rate and pressure compared to higher efficiency pumps.
What is total dynamic head (TDH)?
TDH is the total pressure a pump must overcome, including static lift, friction loss, and pressure requirements.
Can I use this calculator for any liquid?
This calculator assumes water as the pumped liquid. For other liquids, adjust for specific gravity and viscosity.
What is the 3960 constant in the formula?
The constant 3960 is derived from the conversion factors for GPM, feet of head, and horsepower.