Expert Verified Pump Tools Updated 2026

Gear Pump Displacement Calculator

Find accurate flow and volume values using a gear pump displacement calculator. This tool helps engineers and technicians quickly estimate pump performance, improve system efficiency, and select the right pump size.

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Displacement & Flow Calculator

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How to Use the Gear Pump Displacement Calculator

Follow these simple steps to use a gear pump displacement calculator:

  1. 1
    Enter Gear Dimensions: Input gear outer diameter, inner diameter, and gear width.
  2. 2
    Input Number of Teeth (if required): Some calculators use gear teeth data for more precise results.
  3. 3
    Enter Pump Speed (RPM): Add the rotational speed of the pump in revolutions per minute.
  4. 4
    Select Units: Choose units such as cubic centimeters (cc), liters, or cubic inches.
  5. 5
    Click Calculate: The calculator will instantly display displacement and flow rate.
  6. 6
    Review Results: Use the output to verify pump capacity and system compatibility.

Tip: Always double-check input values to ensure accurate results.

How to Calculate Gear Pump Displacement Manually

Learn how to calculate gear pump displacement manually using the standard formula.

Formula

Displacement (V) = π × (Do² - Di²) / 4 × Width

Where:

  • Do = Outer diameter of gear
  • Di = Inner diameter of gear
  • Width = Gear face width

Step-by-Step Example:

Given:
Outer Diameter (Do) = 10 cm
Inner Diameter (Di) = 6 cm
Width = 5 cm

Step 1: Square the diameters
Do² = 10 × 10 = 100
Di² = 6 × 6 = 36

Step 2: Subtract values
100 - 36 = 64

Step 3: Multiply by π / 4
(π × 64) / 4 = 50.27

Step 4: Multiply by width
50.27 × 5 = 251.35 cm³

Final Answer:
Gear pump displacement = 251.35 cm³ per revolution

To calculate flow rate:

Flow Rate = Displacement × RPM

Example:
RPM = 1000
Flow Rate = 251.35 × 1000 = 251,350 cm³/min

Gear Pump Displacement Conversion Chart

Reference table for common gear pump displacement conversions.

Cubic Centimeters Liters
100 cc0.1 L
250 cc0.25 L
500 cc0.5 L
1000 cc1.0 L
2000 cc2.0 L
Cubic Inches Cubic Centimeters
1 in³16.387 cc
5 in³81.935 cc
10 in³163.87 cc
20 in³327.74 cc

For more details, read about electrical voltage on Wikipedia.

Frequently Asked Questions (FAQs)

To calculate the displacement of a gear pump, you need to determine the volume of fluid transferred per revolution. This involves measuring the gear dimensions and the housing cavity to find the exact fluid volume moved in one full rotation of the internal gears, given in cubic inches or cc.

Displacement in a hydraulic gear pump refers to the specific amount of fluid that the pump forces through its outlet during a single complete revolution of its drive shaft. It is typically measured in cubic centimeters per revolution (cc/rev) or cubic inches per revolution (in³/rev).

You can calculate pump displacement from flow rate by dividing the flow rate by the pump's rotational speed (RPM). For example, if the flow rate is measured in gallons per minute, convert it to cubic inches, then divide by RPM to determine the precise displacement per revolution accurately.

Flow rate measures the total volume of fluid moved over a specific period of time, usually expressed in gallons per minute or liters per minute. Displacement, however, is the fixed volume of fluid moved during just one single rotation of the pump shaft, regardless of the operating time.

The capacity of a gear pump is determined by its displacement and operating speed. You can find this capacity by multiplying the pump's displacement per revolution by its rotational speed in RPM. This calculation yields the theoretical flow rate or total capacity in a given timeframe.

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