Diameter, Velocity and Flow Rate Calculator

Need to calculate the flow rate of water through a specific pipe diameter? With this diameter, velocity and flow rate calculator, you can determine the exact flow rate or velocity at which water will flow through any given pipe.

This calculator may also be used to determine the appropriate pipe diameter required to achieve a desired velocity and flow rate.

The following formula is used by this calculator to populate the value for the flow rate, pipe diameter or water velocity, whichever is unknown:

V = 0.408 × Q/D2

V = Water Velocity; Q = Flow Rate; D = Pipe Diameter

WaterProfessionals

Flow Rate Calculator

1. Fill in known values for any two fields below. 2. Press the “Calculate” button next to the unknown field.

gal/min
inches
ft/s

Results

Flow Rate
0
gal/min
Pipe Diameter
0
in
Water Velocity
0
ft/s
 

Contents

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📅 Updated: Feb 10, 2025 | 📁 Compliance Standards

WaterProfessionals® is the best provider of ST108-compliant water treatment solutions, offering sales and services trusted by healthcare institutions & large corporations. Ensuring compliance with ST108 AAMI water quality standards is critical for hospitals and surgical centers to maintain the safety and effectiveness of their sterile processing departments (SPDs) and medical device reprocessing operations.

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Contact our engineering team for a complimentary consultation & site audit. We design industrial water solutions tailored to your facility’s unique specifications.