Gear Pump GPM Calculator
A gear pump GPM calculator helps you quickly determine the flow rate of your pump in gallons per minute. It simplifies complex calculations and ensures accurate system design.
GPM Flow Calculator
How to Use a Gear Pump GPM Calculator
Follow these simple steps to use a gear pump GPM calculator effectively:
- Enter pump displacement: Input the pump displacement in cubic inches per revolution (in³/rev).
- Input pump speed: Enter the rotational speed in RPM (revolutions per minute).
- Add efficiency (optional but recommended): Use volumetric efficiency (typically 85%–95%).
- Click calculate: The calculator will display the flow rate in GPM.
- Always use correct units.
- Check manufacturer specifications.
- Include efficiency for real-world results.
How to Calculate Gear Pump GPM
You can calculate gear pump flow manually using this formula:
Where:
- Displacement = cubic inches per revolution
- RPM = pump speed
- Efficiency = decimal (e.g., 0.90 for 90%)
- 231 = cubic inches in one gallon
Step-by-Step Example
Given:
- Displacement = 2.5 in³/rev
- RPM = 1750
- Efficiency = 90% (0.90)
Step 1: Multiply displacement by RPM
2.5 × 1750 = 4375
Step 2: Multiply by efficiency
4375 × 0.90 = 3937.5
Step 3: Divide by 231
3937.5 ÷ 231 = 17.05 GPM
Final Answer: Flow Rate ≈ 17.05 GPM
Gear Pump GPM Conversion Chart
Assumptions: Efficiency = 100% (ideal condition)
| Displacement (in³/rev) | RPM | GPM |
|---|---|---|
| 1.0 | 1000 | 4.33 |
| 1.5 | 1200 | 7.79 |
| 2.0 | 1500 | 12.99 |
| 2.5 | 1750 | 18.94 |
| 3.0 | 1800 | 23.38 |
| 3.5 | 2000 | 30.30 |
| 4.0 | 2200 | 38.10 |
| 5.0 | 2500 | 54.11 |
Note: Multiply results by efficiency for real-world values.
Frequently Asked Questions (FAQs)
A gear pump GPM calculator is a tool that calculates flow rate based on displacement, speed, and efficiency.
Efficiency accounts for internal leakage and losses. It gives a more realistic flow rate.
Yes. Use the formula: GPM = (Displacement × RPM × Efficiency) ÷ 231.
Most gear pumps operate between 85% and 95% volumetric efficiency.
Flow rate increases directly with RPM. Higher speed means higher GPM.
Yes. Gear pumps are positive displacement pumps, so displacement stays constant per revolution.
It is very accurate when correct inputs and efficiency values are used.
Yes. It is widely used in hydraulic system design and analysis.
Use displacement in cubic inches per revolution (in³/rev), speed in RPM, and the output will be in GPM.
Pressure does not directly change GPM, but higher pressure can reduce efficiency slightly due to increased internal leakage.