Thursday Tip // How to shorten a zipper

Sometimes we get feedback or suggestions for tips from our community of followers. This one is brought to you courtesy of a suggestion from sewist extraordinaire, Lee (she/her) @cottuscognatus. Thanks for the idea, Lee! Also, go give her a follow, she is an inspiration.

If you’ve ever needed a zipper for a project or you are looking to replace a broken zipper in a ready-to-wear (RTW) garment, you probably already know that the exact size of zipper can be hard to come by in your average big box store. Purchasing zippers in bulk at longer lengths and shortening them can be more cost effective if you find yourself needing specific zipper lengths.

Maybe you inherited Nana’s zipper stash or you frequent the thrift store and pick up random bags of notions on the regular. Either way, being able to shorten a zipper is a super useful skill.

There are many types of zippers out there but most commonly you will find metal zippers, molded plastic zippers or nylon coil zippers. Zippers can be closed end/non-separating, open end/separating, two-way zippers, invisible zippers and the list goes on. You can buy zipper tape and all the parts to assemble your own zippers as well.

For this post we are going to cover the most common types of zippers found in home garment sewing. Think of your typical invisible skirt zipper, jeans fly zipper or plastic zipper for a jacket or hoodie.

How to measure zipper length:

Zipper length is determined by the total length of the teeth from the zipper pull to the stopper at the bottom. The zipper tape is not included in the measurement. If you are unsure of the size of zipper you need, it’s best to have one that is longer than necessary and then you can shorten it if needed.

Generally, invisible zippers are shortened from the bottom. Separating/open-end zippers are shortened from the top. Non-separating/closed end zippers can be shortened from the bottom OR top unless they have metal teeth, then they must be shortened from the top.

Shortening a zipper from the bottom:

This method can be used for invisible zips and closed-end plastic or nylon coil zippers.

Measure and mark where you want your zipper to end (ie. the new location of the stopper)

Sew a bartack over the zipper teeth using a very wide zig zag stitch on your machine or hand sew using thread doubled in a hand sewing needle. 

When sewing with a machine make sure to go slow and use your handwheel to test whether your bartack is wide enough to stitch around the teeth. You want the needle to go into the zipper tape on either side of the teeth. If the zipper teeth are too wide you may need to hand sew the bartack.

Cut the zipper about ½”-1” below the new stopper. Use regular paper scissors to cut through the zipper so you don’t dull your good fabric scissors.

If the extra teeth at the bottom of the zipper are in the way for later sewing, you can carefully remove them by cutting the coils parallel to the zipper tape and pulling out the loops or sew a fabric tab over them.

With these types of zippers the bottom stopper isn’t usually visible when the zipper is sewn into a garment. More often than not the fabric is what actually stops the zipper pull so you don’t need to worry about how good the bartack looks or if the thread matches, as long as it is secure.

Shortening a zipper from the top (eg. metal zips):

Measure and mark down to where you want the zipper pull to stop at the top of the zipper.

Using a pair of pliers, pull the metal teeth off above the marking. If you have a pair of metal snips/nippers you can also use those to cut the teeth off. Don’t cut them off with scissors! It will wreck them. 

The teeth don’t come off easily but don’t worry if there is some damage to the zipper tape. You will be sewing over it later and likely won’t notice.

Note: you can also shorten a plastic zipper from the top by using nippers to cut off the “head” of the tooth and then snipping the remaining plastic from the zipper tape. This takes a bit more precision but it’s doable if you have the patience

For coil zippers, use a small scissor to cut the teeth parallel to the tape and then use the tip of the scissors or an awl to pull out the remaining loops.

Remove about an inch of teeth and then, using a flat head screwdriver and/or the pliers, remove the top stoppers.

(This doesn’t really work for plastic stoppers because they need to be molded onto the tape. You would need to be sewing the shortened zipper into a garment right away to secure it with fabric. However, there are zipper replacement parts and repair kits available if you really want to shorten your plastic zippers from the top in this way).

Reattach the stoppers where you marked the new top for the zipper pull. Use pliers to pinch the stopper tightly on the tape. Maybe do it with a towel on your work surface. I definitely lost one of the stoppers among the crumbs on the floor. We’ll pretend there’s two in the next pictures.

Cut the excess zipper tape about 1” above the markings and new stoppers.

And there you have it!