Choosing the right zipper size makes a big difference in how your bag looks and holds up. If you've ever stood in front of the zipper wall wondering whether you need a #3 or a #5, this quick guide is for you. I'll show you the difference side by side, which size I reach for on different projects, and how to add zipper pulls once you've picked your tape.
The Quick Answer
- #3 zipper: a narrower coil (about 3 mm). Best for small and detailed projects like pouches, phone cases, and small bags.
- #5 zipper: a wider coil (about 5 mm) and a sturdier closure. Best for totes, larger pouches, and everyday bags that get opened and closed a lot.
Match the zipper to the project: #3 for delicate, detailed work and #5 for durable, high-use bags.
What Do the Numbers Mean?
The #3 and #5 refer to the width of the zipper's coil or teeth when the zipper is closed. The bigger the number, the wider and stronger the zipper. In the photo below, the #5 zipper is toward the top and the #3 is toward the bottom.
When to Use Each Size
| Project | Zipper size | Why |
|---|---|---|
| Small pouches, coin purses, phone cases | #3 | A narrower zipper looks proportional and is easier to sew on small pieces. |
| Detailed or dainty bags | #3 | A delicate closure suits a finer look. |
| Totes and larger pouches | #5 | A wider coil stands up to heavier loads. |
| Everyday carry bags | #5 | Built for frequent opening and closing. |
How to Add Zipper Pulls
Once you've picked your zipper size, adding custom pulls gives your bag a finished, professional look. My 2-minute zipper jig demo shows how to attach pulls quickly and securely to #3 or #5 zipper tape. For more detail, see my Attaching Zipper Pulls to Zipper Tape tutorial.
Practice Project: A 10-Minute Zipper Pouch
The best way to get a feel for each size is to sew with it. This 10-minute zipper pouch video is a perfect way to try both #3 and #5 zippers in a real project. Want to make stand-up pouches in three sizes? Grab my Easy Zipper Cases pattern or an all-in-one Easy Zipper Cases Kit.
Zipper Size FAQ
What is the difference between a #3 and #5 zipper?
The number is the approximate width of the coil in millimeters when the zipper is closed. A #3 is narrower and more delicate. A #5 is wider and sturdier.
Which zipper size is best for a zipper pouch?
For small pouches, a #3 looks proportional and is easy to sew. For larger pouches or ones you'll open and close every day, a #5 is a great choice.
What size zipper should I use for a tote bag?
Use a #5. Totes carry more weight and get used often, so the wider, stronger coil holds up better.
Can I use #3 zipper pulls on #5 zipper tape?
No. Zipper pulls are made to fit a specific size, so match your pulls to your tape: #3 pulls on #3 tape and #5 pulls on #5 tape.
Can I sew over the zipper teeth?
With nylon coil zippers like Sew Hungry Hippie zippers, yes. They can look like metal, but the nylon coil lets you sew and cut right through it.
More Zipper Tutorials
- How to Sew Straight Zippers
- 4 Tips for Zipper Tab Corners Without the Crunchy Bunchy Look
- How to Make Perfect Zipper Pockets
- How to Attach Metal Zipper Ends
- Patchwork Zipper Pouch Tutorial
Shop zippers and zipper tape, kits, patterns, and tools and notions in the Sew Hungry Hippie shop.
Thanks for sewing along! If this helped, please subscribe on YouTube and join our email list for new tutorials, boxes, and restocks.
Peace, Love, Sewing,
-Natalie
