Inches of Water to GPM Calculator

If you're looking to calculate the flow rate of a liquid in gallons per minute (GPM) based on the pressure reading in Inches of Water, then you're in the right place! Our Inches of Water to GPM Calculator is a simple and user-friendly tool designed to provide you with accurate results in no time. With just a few clicks, you can calculate the flow rate of your liquid based on pressure readings in Inches of Water, without needing extensive technical knowledge or specialized equipment. Whether you're a homeowner trying to figure out how much water your well pump is pushing or an engineer working on a fluid flow project - this calculator is here to help. So, let's dive into how it works and how you can use it to your advantage!

Inches of Water to GPM Calculator

Convert inches of water to gallons per minute (GPM).

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Inches of Water to GPM Calculator Results
Inches of Water0
Pipe Diameter0
Pipe Length0
Water Temperature0
Gallons per Minute (GPM)0

converting between inches of water and psi is essential for pressure measurements. Our inches of water to psi calculator aids in this conversion. To gain insights into related pressure calculations and understand their implications, link it with our water pressure calculator. This tandem approach offers comprehensive tools for pressure analysis.

The Inches of Water to GPM Calculator is a valuable tool for those in the plumbing industry. It allows you to convert pressure in inches of water to gallons per minute (GPM), which is essential for sizing pipes and selecting the right pump for your system.

Instructions for Utilizing the Calculator:

To use the Inches of Water to GPM Calculator, you need to input the following information:

  • Inches of Water: The pressure in inches of water at the point of measurement.
  • Pipe Diameter: The diameter of the pipe in inches.
  • Pipe Length: The length of the pipe in feet.
  • Water Temperature: The temperature of the water in degrees Fahrenheit.
  • Elevation: The vertical distance between the point of measurement and the discharge point in feet.

Once you've entered the required data, click the "Convert" button, and the calculator will display the GPM value.


The formula used in this calculator to convert inches of water to GPM is as follows:

GPM = (Velocity x Area) / 231

Where: Velocity = √((2 x Inches of Water x 12 x 32.2 x Elevation) / (Pipe Length x Pipe Diameter^2 x (1 + (0.000704 x (Water Temperature - 60))))) Area = Pipe Diameter^2 x 0.7854

Illustrative Examples:

Suppose you want to determine the GPM of a pipe with a pressure of 40 inches of water, a diameter of 2 inches, a length of 100 feet, a temperature of 68 degrees Fahrenheit, and an elevation of 50 feet. In that case, the calculator will display a GPM value of 12.06.

Illustrative Table Example:

The following table demonstrates how the Inches of Water to GPM Calculator can be used to calculate the GPM of pipes with different sizes and water pressure levels.

Inches of WaterPipe DiameterPipe LengthWater TemperatureElevationGPM

In conclusion, the Inches of Water to GPM Calculator is an invaluable tool for plumbing professionals. It helps them to determine the required GPM for a given pipe size and pressure level, which is crucial for proper system design and pump selection. By following the simple steps outlined in this blog post, you can easily use the Inches of Water to GPM Calculator to calculate the GPM of your pipes. Remember, knowing the GPM of your pipes will help you create efficient plumbing systems that meet your needs.

About the Author

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Siam Anik
Plumbing Engineer

Siam Anik is a Bangladeshi plumbing engineer who graduated with a degree in mechanical engineering and has over 7 years of experience in the plumbing industry.