Plumbing Pipe Sizes


The following pipe sizes are the minimum required pipe size for single fixtures and are subject varying code regulations. When other fixtures are added to the same pipe, the size may increase.





Drainage sizes

Fixture spacer Size in Inches spacer Size in Millimeters
Bathtub spacer 1.5 spacer 38
Beer cabinet spacer 1.5 spacer 38
Bidet spacer 1.25 spacer 32
Clothes washer spacer 2 spacer 50
Dishwasher spacer 1.5 spacer 38
Floor drain spacer 2 spacer 50
Laundry tub spacer 1.5 spacer 38
Lavatory - single or double(bathroom sink) spacer 1.25 spacer 32
Shower 1 head spacer 1.5 spacer 38
shower 2-3 heads spacer 2 spacer 50
Kitchen Sink - single or double spacer 1.5 spacer 38
Toilet / water closet spacer 3 spacer 76

Water supply pipe sizes

Fixture spacer Size in Inches spacer Size in Millimeters
Bathtub spacer .5 spacer 15
clothes washer spacer .5 spacer 15
Dishwasher spacer 1/2 spacer 15
Hose bibb spacer 1/2 spacer 15
Lavatory spacer 3/8 spacer 10
Kitchen sink spacer 1/2 spacer 15
Shower head spacer 1/2 spacer 15
Water closet (tank type) spacer 3/8 spacer 10