H2X Tools

Pipe Velocity Calculator

Calculate the velocity of fluids flowing through pipes easily using the Pipe Velocity Calculator
Get accurate results with this simple, yet powerful tool.

What is the Pipe Velocity Calculation Used For and Why is it Important?

Pipe velocity is the speed at which fluid flows through a pipe and is usually measured in terms of m/s or ft/s.

It’s important to know what your pipe velocity is because it relates closely to frictional losses. The higher the velocity of a fluid, the higher the friction loss is.

High friction loss affects the pump’s performance and other related equipment, which might mean you have to opt for bigger pumps.

Larger pumps and equipment can increase the capital cost of the building and also increase the operational cost to run the building. So this calculation is vital when designing a system.

pipe velocity calculator

Pipe Velocity Formula

As the calculation can be measured in terms ft/second and m/second, there are two different calculation methods to establish pipe velocity:

Pipe velocity calculation formula

The Imperial Equation

The following equation can be used to calculate the pipe velocity:

v=0.0408 Velocity Calculator free to use h2x engineering

Components of the Equation

V = Water velocity inside the pipe (ft/second)

Q = Water flow rate inside the pipe (GPM)

D = Pipe inside diameter (inner diameter) (in)

The Metric Equation

The following equation can be used to calculate the pipe velocity:

v=1.274 Velocity Calculator free to use h2x engineering

Components of the Equation

V = Water velocity inside the pipe (m/second)

Q = Volume flow (m³/second)

D = Pipe inside diameter (inner diameter) (m)


Pipe Diameter and Water Flow Rate

The water flow rate


The pipe diameter

Water Flow Rate

The flow rate of the fluid is the volume of fluid that passes through an area in a unit of time. It is measured in m³/s, GPM, or l/s and is directly proportional to the pipe flow velocity.

Pipe Internal Diameter

There is an inverse relationship between the internal diameter of a pipe and the pipe velocity. This means that the water velocity will increase as the pipe diameter decreases

Use h2x for Pipe Velocity Calculations

Calculates the pipe velocity through every pipe (CIBSE-verified)

Design to different velocities for various water systems (CIBSE-verified)

Automates all of the calculations based on your design layout

h2x is CIBSE-verified design software built to improve the efficiency and quality of your design process.

The automated calculations for flow rates, velocities, pressures, pump duties, plant sizing, and recirculation systems mean that you can focus on your project’s design instead of undertaking tedious calculations.

The straightforward user interface helps engineers produce high-quality designs and work more efficiently, all while adhering to industry regulations.

The software has already been used to size millions of kilometres of pipes in projects across the world.

Why Use a Pipe Velocity Calculator?

There are several benefits of using a Pipe Velocity Calculator, including:


  • Increased Accuracy: The Pipe Velocity Calculator provides accurate results, eliminating the possibility of human error when calculating fluid velocity by hand.
  • Time-Saving: The Pipe Velocity Calculator saves time by providing quick and easy calculations, eliminating the need to perform complex mathematical calculations manually.
  • Easy to Use: The Pipe Velocity Calculator is user-friendly and requires no special training or technical knowledge.
  • Cost-Effective: Using a Pipe Velocity Calculator can save money by reducing the time spent on manual calculations and avoiding costly mistakes.


The velocity of a fluid flowing in a pipe can be calculated using the following equation:

v = Q / A

v is the velocity of the fluid, in meters per second (m/s)

Q is the volumetric flow rate, in cubic meters per second (m^3/s)

A is the cross-sectional area of the pipe, in square meters (m^2)

See What H2X Can Do

There is a reason we are rated 4.9/5 for customer support on Capterra. Our integrated help button means that a real engineer will assist with any design query, no matter how big or small.