The size of a zipper is measured from the top stopper to the bottom stopper. Don’t measure the length of the cloth tape the zipper is attached to.

If you’re not sure about the length you need, it is better to buy a zipper that is too long rather than too short. You can always cut a zipper down to the size you need, if you’re working with a close-end zipper. Just cut at the length you want and create a bottom or top stopper by sewing back and forth over the zipper tape.

If you want an open-end or separating zipper, you must buy the exact size that is required for your project.

Adding a zipper to a sewing project can be intimidating, but you can get a long way with just a few basics and the right tools. How you install a zipper can depend on your project, function, or a particular aesthetic.

Here are 5 common ways to install a regular zipper:

A finishing with an even amount of fabric on each side of the zipper.

Although the zipper is not exposed, you don’t use an invisible zipper for this technique. Typically a centered zipper is called a centered zipper because it’s on the center back or centered front seam.
Used for skirts, blouses, and dresses in a center-back seam but can also be used on a side seam.

The “lap” in a lapped zipper refers to the fold of fabric on the left side that covers the zipper. This fold of fabric is sometimes referred to as a placket.

You see this most often on garments, especially along a front, back, or side seam.

This is similar to a centered zipper, but here the top and bottom of the zipper are sewn across. Your stitching forms a rectangle. The zipper's opening allows just enough room to get the dress on.

For home décor, you might use this technique on a pillow back. You may also have seen this on special occasion garments within a fitted side seam.

In an exposed zipper installation all the teeth and part of the tape to either side of the teeth are exposed.

This is a common technique in sportswear, accessories and a lot of home decor projects.

It’s pretty obvious that the zipper sewn into the fly front opening of a pair of jeans, trousers or pants is a very specific process. It's sewn underneath, leaving only the curved topstitching on the outside visible.

Installing a zipper requires a zipper foot. A zipper foot has a narrow tip, which allows you to stitch close to the coil. Most sewing machines come with a zipper foot to sew a regular zipper.

You need a zipper, 2 fabric pieces, a zipper foot, and thread to install a zipper with your sewing machine.