Fixtures Trap Sizes

Recommended drain trap sizes for different types of fixtures

Fixtures Trap Sizes

Recommended drain trap size for different types of fixtures based on plumbing standards.

Fixture	Trap Size (in)	Trap Size (mm)
Bathtub	1 1/2	38.1
Bidet	1 1/2	38.1
Dishwasher	1 1/2	38.1
Drinking fountain	1 1/4	31.75
Floor drain	2	50.8
Kitchen sink	1 1/2	38.1
Laundry tub	1 1/2	38.1
Lavatory	1 1/4	31.75
Public toilet	Integrated	Integrated
Shower	2	50.8
Toilet	Integrated	Integrated
Urinal	2	50.8
Washing machine	2	50.8

Calculator

Inputs

Trap Size (in)

Results

Trap Size-- mm