Qatium uses the same units as the EPANET engine, either customary (US) or international system (SI) depending on the units present in source data that's uploaded into Qatium.

International System | US Customary system | |
---|---|---|

Network length | km | mi (mile) |

Element length | m | ft |

Flow / Assigned demand | l/s | gal/min |

Height | m | ft (feet) |

Pressure (max, min, mean) | m | psi (pound per square inch) |

Headloss | m/km | ft/kft (feet/kilofeet) |

Volume | m^{3} |
ft^{3} |

Capacity / Average error (model deviation) / Relative speed (pump) | % | % |

Velocity | m/s | ft/s (feet per second) |

Pipe diameter | mm | in (inches) |

Tank diameter | m | ft |

Upstream / Downstream pressure | m | psi (pound per square inch) |

Power | kw | hp |

Elevation | m | ft |

Relative head | m | ft |

Water age | h | h |

## How do we know what unit is your network in?

To determine the unit system of the network, Qatium performs checks on the diameter field of pipe files, which consist of 3 stages:

**Filtering:**we accept values within the range from 1 to 4,000**Classification by file:**we check if each file can belong to*US Customary*when

- the value of the maximum diameter is less than 150
- the value of the minimum diameter is less than 15

If neither of the conditions is met, the file is set as *International System.*

**Setting the network unit system: **if any of the pipe files was set as *International System*, the network unit is also set as *International System*. Otherwise it is set as *US Customary*.

Please tell us if you are having trouble with units in Qatium.