Hose Barb size

Hose Barb Size

1/2" hose barb measures 0.50" OD
3/4" hose barb measures 0.75" OD
1" hose barb measures 1.0" OD
1.5", 2", 2.5", 3", 4" measure 1.50, 2.0, 2.50, 3.0, 4.0" respectively.
This is the standard for hose barbs for sanitary fittings.

This may not be standard for other industries and often is not. For example, hose barbs used for hydraulic fluid hose/tubing are larger than the stated size.

Hose barbs used for "beverage tubing" (for example in the soda industry and beer dispensing lines in bars/restaurants) or often larger than the stated size.