Plumbing Calculators
Pipe flow, velocity, pressure loss, pipe volume and water heater sizing with the formulas plumbers and engineers use.
Most used
Pipe flow
- Pipe Flow & Water Velocity CalculatorWater velocity from flow rate and pipe size, or flow rate from velocity.
- Water Pipe Size Calculator (Velocity Method)Smallest copper, PEX or PVC pipe that keeps water velocity under a limit.
- Pipe Volume CalculatorGallons of water held in a length of pipe, and its weight.
- Pipe Pressure Drop Calculator (Hazen-Williams)Friction pressure loss in a water pipe plus elevation change.
Water heaters
Questions
Are these results code-compliant pipe sizes?
No. Plumbing codes (IPC, UPC and local amendments) set sizing by fixture units and other rules. These tools give engineering estimates you can check against code.