PEX Tubing Sizing Calculator

Size PEX tubing for water supply per UPC/IPC requirements

Fixture Units

System Parameters

UPC/IPC limits velocity to 8 ft/s for water supply

Recommended PEX Size

Minimum PEX Size --
Actual Velocity --
Total WSFU --
Demand Flow (GPM) --
Pressure Loss --
Remaining Pressure --
Note: PEX has smaller inside diameter than copper. Size up if replacing copper pipe.

PEX Size Reference

Nominal Size OD (in) ID (in) Max GPM @ 8 ft/s
3/8" 0.500 0.350 2.4
1/2" 0.625 0.475 4.4
3/4" 0.875 0.681 9.1
1" 1.125 0.863 14.6
1-1/4" 1.375 1.063 22.1
1-1/2" 1.625 1.263 31.3
2" 2.125 1.653 53.5

PEX Installation Guidelines

Temperature Rating

180F max continuous

200F peak

100 PSI @ 180F

Bend Radius

6x OD minimum

Use support at bends

Avoid kinks

Support Spacing

32" horizontal

48" vertical

Per manufacturer

UV Protection

No direct sunlight

30-60 day max exposure

Use sleeve outdoors