Whether you’re designing a baby bib, a canvas bag, or a rugged work jacket, choosing the right size of snap fastener buttons can make or break your final product. In this guide, we’ll explain what snap button sizes mean, how to choose the right one for your fabric and function, and tips to get a clean, secure fit.
🔍 What Do Snap Button Sizes Mean?
Snap fasteners are often measured by cap diameter — the top visible round part. Common sizes include:
| Size Code | Diameter (mm) | Best For |
|---|---|---|
| #10 | 10 mm | Light fabrics, babywear, accessories |
| #12.5 | 12.5 mm | Shirts, light jackets, tote bags |
| #15 | 15 mm | Medium jackets, kids’ wear, uniforms |
| #17 | 17 mm | Workwear, canvas, bags |
| #20+ | 20 mm or more | Heavy coats, outdoor gear |
💡 Tip: Sizes may vary slightly by manufacturer, so always check the product specs before ordering.
📐 How to Choose the Right Snap Fastener Size
Here are the key factors to consider:
1. Fabric Thickness
- Thin fabric (cotton, linen): Use 10–12.5 mm snap buttons.
- Medium fabric (denim, canvas): Use 15–17 mm snaps with long prongs or caps.
- Thick/padded fabric (outerwear, leather): Use 17 mm+ heavy-duty snaps.
2. Function & Stress Level
- For high-tension areas (cuffs, closures under strain), go with larger snaps for better grip.
- For decorative or light-use purposes, smaller snaps are usually enough.
3. Aesthetics
- Smaller snaps look more delicate and refined.
- Larger snaps are bold and can make a design statement.
4. Ease of Use
- In babywear or adaptive clothing, bigger snaps are easier to open and close.
🛠 Snap Length Matters Too
Not just the cap size, but also the post or prong length should match your fabric:
- Standard posts (3–4 mm): For 1–2 layers of cotton or jersey.
- Long posts (6 mm+): For padded, quilted, or multi-layer materials.
⚠️ Too short = won’t hold. Too long = may wobble or damage fabric.
🧰 Recommended Sizes by Application
| Project Type | Suggested Snap Size |
|---|---|
| Baby clothes/bibs | 10–12.5 mm plastic or metal snaps |
| Shirts & dresses | 12.5–15 mm |
| Handbags & wallets | 15–17 mm |
| Workwear/jackets | 17–20 mm heavy-duty snaps |
| DIY crafts/leather | Depends on thickness – 15 mm+ recommended |
✅ Quick Checklist Before You Buy
- What fabric are you using?
- What is the snap’s function — strength or style?
- Do you have the right tools for installation?
- Will you need a custom color or logo cap?
🔚 Final Thoughts
A well-chosen snap fastener button improves your product’s functionality, style, and durability. Whether you’re sewing at home or designing for your brand, take time to select the right size, length, and material to match your project needs.
