Plumbing Calculators
Last updated .
This hub is domestic hot water. The storage path adds up the uses in one busy hour and compares that total with a first-hour rating. The tankless path adds the fixture flows you type and subtracts incoming water from the outlet you want.
The BTU and kilowatt figures are information about warming that flow. They are not a furnace load, and they are not a wire or breaker size. A horizontal drain is the fall over the run, checked against the IRC minimum for that diameter.
Which calculator do I need?
| Job | Open |
|---|---|
| Storage peak hour or tankless flow | Water heater size |
| Fall over a drain and the IRC minimum | Pipe slope |