Zippers By Gauge
Zipper gauge (also called size or chain size) is the width of the teeth when the zipper is closed. A #3 zipper measures about 3mm across the teeth; a #5 measures about 5mm; a #10 measures about 10mm and is considered heavy duty.
Use gauge to match a replacement zipper to the original, or to pick strength for a new project:
• #2–#3 — lightweight: pouches, coin purses, dresses, children’s garments, fine bags
• #4.5–#5 — medium weight: jeans, jackets, sportswear, pockets, most apparel
• #7–#8 — mid-heavy: outerwear, bags, marine and outdoor projects
• #10 — heavy duty: work jackets, tents, sleeping bags, industrial and leather goods
The slider must match the same gauge and tooth type. If you are unsure, measure the old zipper teeth or send a photo — we can help you choose.