Convert zipper numbers like #3, #5, #8, and #10 into approximate chain width in millimeters and inches. You can also enter a measured zipper width to find the nearest common size.
Choose a zipper number or enter the width you measured across the closed teeth.
About 5 mm across the closed teeth.
The number on a zipper is usually the approximate width of the closed teeth or coil in millimeters. A #3 zipper is about 3 mm wide, a #5 zipper is about 5 mm wide, and a #10 zipper is about 10 mm wide.
This is most useful when replacing a slider, choosing zipper tape for a sewing project, or comparing patterns that call for a different zipper size system.
| Size | MM | Inches | Common uses |
|---|
Usually, yes for practical sizing. A #5 zipper is generally about 5 mm wide across the closed teeth or coil, though small brand and style differences are normal.
Use the size as a starting point, then match the slider to the zipper type too. A #5 coil slider, #5 metal slider, and #5 molded plastic slider are not automatically interchangeable.
#5 is common for purses, pouches, backpacks, and many bags. #8 or #10 is better for heavier gear, luggage, outdoor covers, and projects that need a larger tooth.