Determining Correct Zipper Length

Zippers are always measured from "component to component" (end stops), regardless of zipper style.
The illustrations below will assist you in determining the proper method for arriving at the desired zipper length.
Zipper-Length-Closed-End-Trouser

CLOSED END
(TROUSER TYPE)

Zipper-Length-Open-End-Jacket

OPEN END
(JACKET TYPE)

Zipper-Length-Tu-Way-Open-End-Jacket

TU-WAY OPEN END
(JACKET TYPE)

Zipper-Length-Bag-Type

BAG TYPE

Zipper-Length-Coverall

COVERALL

The fabric at the ends of the zipper are never used in the length calculation. The length of a zipper is always considered to be the operating length, not the total length.