How Do You Measure a Zipper Size for a Repair?

Measure the teeth, not the slider. Zipper Shipper explains that zipper size, also called gauge, is the width of the teeth in millimetres when the zipper is closed, and that the markings on the back of a slider can mean different things depending on the maker.

What the guide says

• Gauge is shown with a number and a hash sign, for example #5. The larger the number, the heavier the zipper.
• Measure the teeth horizontally when the zipper is closed, without including the tape.
• You can use a ruler, tape measure or digital caliper.
• Numbers on the back of the slider can mean different things depending on the manufacturer, so measuring is the most reliable way.
• If a zipper no longer closes, measure one side and double it. You may need to round slightly up or down.
• Zipper Rescue says to match a replacement slider to the correct size and type.

What to do

1. Close the zipper, if you can.
2. Measure the width of the teeth in millimetres.
3. Note whether the teeth are coil, plastic or metal.
4. Check the slider’s back for a number, but do not rely on it.
5. Take the information, and a photo, to the shop.

Why the type matters

A slider made for one type of teeth may not work on another, so size alone is not enough.

If you cannot tell the type of teeth by eye, look at the back of the zipper: a coil zipper has a continuous spiral of thread-like teeth, while a molded plastic or metal zipper has individual teeth. Photograph both sides before you order.

Where this answer stops

This is general guidance from a zipper seller. Some zippers are unusual sizes, and a repair shop or specialist supplier can match the part from the old slider.