Pipe sizing made simple
Calculate the required pipe diameter from flow rate and fluid velocity in seconds.
Pipe Diameter Calculator is a practical engineering tool for quick pipe sizing calculations. Enter the required flow rate and desired fluid velocity, choose your units, and calculate the corresponding internal pipe diameter.
Fast pipe diameter calculations
without unnecessary complexity
Designed for situations where flow rate and desired velocity are known and you simply need to determine the required pipe diameter.
Pipe diameter
Calculate the required internal pipe diameter from flow rate and fluid velocity.
Flow rate
Enter the required volumetric flow using the engineering units appropriate for your project.
Fluid velocity
Define the desired velocity and immediately see the corresponding pipe diameter.
Metric units
Work with commonly used SI and metric engineering units.
Imperial units
Switch to Imperial and US customary units when required.
Quick engineering checks
Useful for preliminary sizing and fast checks while working in the field or at your desk.
From flow requirement to pipe diameter in three steps
Enter flow rate
Specify the required volumetric flow rate.
Set velocity
Enter the desired fluid velocity for the pipe.
Calculate diameter
Get the required internal pipe diameter instantly.
Based on the continuity equation
Pipe Diameter Calculator uses the fundamental relationship between volumetric flow rate, flow velocity and pipe cross-sectional area.
This makes it ideal when pressure loss is not part of the calculation and you simply want to estimate the pipe diameter required for a specified flow and velocity.
A useful pocket tool for engineering work
👨🔧 Engineers
Quickly estimate pipe sizes during preliminary design and system checks.
🛠️ Technicians
Perform quick pipe sizing checks in the field without opening a full engineering package.
🎓 Students
Explore the relationship between flow rate, velocity and pipe diameter.
Need advanced pipe flow calculations?
Pipe Flow Calculations also provides professional engineering tools for pressure drop, flow rate, gas flow, orifice plates, valves, pipe networks and other fluid-flow calculations.
Explore the desktop engineering suite →Calculate pipe diameter wherever you work
A fast and focused pipe sizing calculator for Android.
Engineering tools by Pipe Flow Calculations