Plumbing Fixture Flow Calculator
Estimate total connected plumbing-fixture flow and a preliminary simultaneous-use flow from editable fixture counts, individual rates and a diversity factor.
Default project preview
9.6 gpm
Shower connected flow
4 gpm
Faucet connected flow
6 gpm
Toilet-fill connected flow
6.6 gpm
Other connected flow
2.5 gpm
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Connected flow = sum of fixture count × entered fixture flow. Preliminary simultaneous flow = connected flow × simultaneous-use factor.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Plumbing Fixture Flow Calculator questions
Is connected flow the expected normal demand?+
No. It represents every entered fixture flowing at once. The diversity factor creates a simpler simultaneous-use planning value.
Can this replace a fixture-unit calculation?+
No. Plumbing codes and utility requirements may use fixture units, pressure and developed length rather than a simple percentage.
Why include toilet fill-valve flow?+
A toilet can draw water while refilling, although the duration and actual fill-valve rate vary.