
Free plumbing tool
Pipe Diameter Selector
Get a practical pipe recommendation in seconds using flow rate, pipe run length, and a conservative velocity target.
Built for fast first-pass sizing. Always confirm the final selection against the manufacturer chart and local plumbing requirements.
Enter your line details
Use the expected line flow and full run length. The tool updates instantly once the inputs are valid.
Browse related pipe products
These catalog items are pulled from RAMO plumbing categories so you can move from sizing into product selection.
Pipe selector FAQ
Built for fast first-pass sizing. Always confirm the final selection against the manufacturer chart and local plumbing requirements.
How should I estimate flow rate?
Add the expected simultaneous demand on the line, not the total building demand. For a quick estimate, sum the fixtures that are likely to run at the same time.
Why does pipe length matter?
Longer runs increase friction loss. The same flow can need a larger diameter when the route is long enough to create a noticeable pressure drop.
Does this replace a full hydraulic design?
No. It is a fast screening tool for practical selection. Final sizing should still be checked against the exact product system, pressure conditions, and local code.
What pipe range does the tool cover?
The selector works across common 16 mm to 63 mm SP / multilayer nominal sizes, which covers most branch and distribution lines used in light building services.


