Pipe Diameter Calculator
Calculate pipe diameter from flow rate and average velocity.
How to use this calculator
What to enter
Enter or select the following as requested: Flow rate (m³/s); Velocity (m/s). Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The fluid-mechanics result is derived from the flow, pressure, density, viscosity, geometry, elevation, or efficiency values entered. Check SI units, whether pressure is absolute or gauge, the assumed flow regime, and whether losses or local fittings are included.
When to use it
Use this for preliminary fluid-flow analysis or equipment sizing. Validate assumptions and manufacturer data before using the result for a real pump, pipe, or safety-critical system.