- 1 What You’ll Need
- 2 How to Sew a Zipper Step by Step
- 2.1 Removing the Old Zipper
- 2.2 Prepare Your New Zipper
- 2.3 How to Sew an Exposed Zipper
- 2.4 How to Sew an Invisible Zipper
- 3 All Zipped Up
It’s happened to all of us. You’re heading out the door, putting on your favorite jacket, and the zipper bites the dust. Time to throw out that jacket? It doesn’t have to be. If you know how to sew a zipper, your favorite jacket, backpack, trousers, or other item can be ready to use again in no time.
What You’ll Need
Fixing your zipper isn’t hard, but you need the right tools for the job. Here’s what you’ll need to follow our tutorial.
A Replacement Zipper
Consider your replacement zipper carefully. You may want to choose something similar to your old zip. Or you might want to choose something better. Either way, think about the following.
Measure different types of zippers differently. Your measurements should include the zipper but not the zipper tape (the part that you will be sewing).
Measure closed-bottom zippers from the bottom stop to the top stop.
Measure separating-bottom zippers from the box (that metal square at the bottom) to the stop pin (that larger bit that keeps the puller from running off at the top).
The resulting measurement will give you the length, in inches or centimetres, of your new zipper.
Gauge refers to the thickness of the zipper. Heavier items use heavier gauge zippers. The higher the gauge number, the larger the teeth of your zipper. 
The gauge number roughly corresponds to the size of the teeth. To measure the teeth, start at the left side and measure all the way across. The millimeter measurement will give you a rough idea of the gauge. If the teeth part of your zipper measures 3.1 to 3.5 millimeters across, for example, the gauge is #3.
Style and Material
There are a lot of different kinds of zippers out there. Here are some of the most common ones.
The conventional zipper design has individual metal teeth lined up at intervals along the zipper tape.
Coil zippers are made from coils of nylon or polyester sewn into the zipper tape. They’re popular in luggage and camping gear. Their design makes it easy to fix an out-of-alignment zip. They are also very strong.
Invisible zippers disappear into the seam of an item. You might find these in dresses and skirts. Any type of zipper can be an invisible zipper. “Invisible” refers to the way it’s sewn into an item, rather than to a specific zipper design.
Open-bottom zippers (or separating-bottom zippers) open all the way. Jacket zippers are an example. Conversely, closed-bottom zippers stop at the bottom. Trouser and dress zippers are generally closed-bottom zips.
Two-way separating zippers can zip open and shut in both directions. These are common in tents and luggage.
The Correct Presser Foot
You can use an ordinary presser foot to sew a zipper, but it might prove more difficult in tight places.
A zipper foot is made for this task. It’s smaller than a standard presser foot and you can adjust some of them to either side as needed. Zipper feet also come in a range of sizes.
The great news is, a zipper foot comes standard with many sewing machines. And if one didn’t come with yours, they’re inexpensive and easy to find.
There are many different kinds of zipper feet, including:
- Zipper foot/piping foot: the standard, narrower zipper foot
- Invisible zipper foot for sewing invisible zippers
- Adjustable zipper foot: can be used on either side of the needle
Check out this zipper foot in action.
You will also need:
- Fabric marking pen
- Seam ripper
- Stabilizing tape or fusible interfacing
- An iron to press the seam
- Scissors for shortening plastic or coil zippers
- Metal snippers and jewelry pliers for shortening metal zippers (I like this set from WorkPro)
Do you have everything you need? Great. Let’s go.
How to Sew a Zipper Step by Step
How you sew in your new zipper will depend on the type of zipper. Are you replacing an invisible zip? Or will your new zipper show? Either way, the first step is taking out the old one.
Removing the Old Zipper
No matter what kind of new zipper you’re installing, the first step is to take out the old one. For this, you’ll need your seam ripper.
First, locate the rows of stitches that hold the zipper in place. Now use the point of your seam ripper to gently lift a stitch. Slide the stitch along the curved cutting edge until it breaks. Now remove the rest of the stitches until your zipper comes free.
Prepare Your New Zipper
It’s easiest to buy a zipper that’s exactly the same size as the old one. But what if you can’t find one? Or what if you have another zipper that would look great but is slightly too long? Never fear. You can use that one too.
First, measure your old zipper. Next, use your fabric pen to mark the new length on the zipper tape of the new zipper. Then hand-sew a succession of whip stitches around the teeth where you want the new bottom to be. You can machine sew a bar tack for this part, provided you’re very, very precise about your stitch length. 
Finally, trim your new zipper. If you have a plastic, nylon, or polyester zipper, you can use ordinary scissors. If your zipper is metal, you’ll need to use metal snips.
Watch how it’s done below.
How to Sew an Exposed Zipper
Sewing an exposed zipper is a bit easier than sewing in an invisible one. Still, since everyone will be seeing your new zip, it pays to do it right.
Step 1: Mark
You’ll use your fabric marking pen to make two marks on the wrong side of your fabric. First, make a mark three-quarters of an inch from the top of the seam. Then lay your zipper along the seam so that the top of the teeth meet that mark.
Now, make a second mark right below the box (the metal bottom) of your zipper.
Set the zipper aside.
Step 2: Stabilize (Optional but recommended)
Stabilize your seam edges by ironing a strip of stabilizing tape or a one-inch wide strip of fusible interfacing onto the seam edges. Do this on both edges, on the wrong side of the fabric.
Step 3: Stay-Stitch
Next, stay-stitch the fabric three-quarters of an inch (1.9 centimeters) from the edge of each seam. 
Step 3: Close the Seam
Now, using a ⅝-inch (1.6 cm) seam allowance, sew the edges of the seam together starting ever-so-slightly below where the box (bottom) of the zipper will sit, and ending at the end of your work.
Step 4: Clip and Press
Clip from the edge of the seam to the seam allowance at the base of the zipper opening. Press the seam allowance open.
Now press open the seam above the cut. Press it open to the seam allowance.
Step 5: Pin and Baste
Pin your zipper along the seam, so that the right side of the zipper is facing up through the right side of the fabric. If you want to baste the zipper to the fabric, do so now.
Step 6: Trim
Double-check the wrong side of the fabric. If necessary, trim the seam allowances.
Step 7: Stitch
This step is easier if you begin with the zipper unzipped.
Starting at the top pin, stitch along the right side of the fabric, between one eighth of an inch (3 millimeters) and one quarter-inch (6 millimeters) from the zipper teeth.
When you get to the bottom, stitch around the box of your zipper, rotate your work, and continue up the other side to the other top pin.
When you’re finished, remove any basting stitches.
How to Sew an Invisible Zipper
An invisible zipper hides in the seam of a garment. You won’t see any machine stitching on the right side of the fabric. This is a popular type of zipper for different types of garments where a zipper would ruin the line of the garment or the pattern of the fabric.
Sew your invisible zipper in while the pieces of your pattern are flat and unattached. An invisible zipper foot is designed to sew invisible zippers, though you can use a regular zipper foot, or even a regular presser foot.
Step 1: Prepare the Seam Edges
If you want to serge your seam edges, now is the time. Alternately, you can secure your edges with stabilizing tape or fusible interfacing.
Step 2: Mark
As with a visible zip, use your fabric marker to make a mark ¾ of an inch from the top of the fabric, on the right side of both pieces.
Also mark a ⅝-inch seam allowance on the right side of both pieces. You will place the zipper along these marks.
Step 3: Pin the First Side of Your Zip
Lay the coil (or teeth) of your zipper right on the seam allowance marking. Lay it face down and pin it into place. Pay close attention to the directionality of your zip, because it’s easy to get this part wrong. The teeth should face away from the edge of the fabric.
If you want to baste the zipper into place, you can do that now.
Step 4: Sew the First Side
Again, sewing your zipper is easier if the zipper is open.
Place the zipper coil (or teeth) under the groove on your invisible zipper foot. Start at the top edge of the fabric and stitch down until you are parallel with the box. Make a bar tack and cut your thread.
Step 5: Pin the Second Side
Now pin the second side to the other piece of fabric and baste if desired. Again, the teeth should face away from the fabric’s edge. Your zipper will look twisted, and that’s okay. You’ll be untwisting it soon enough.
Step 6: Sew the Second Side
Following the same procedure as in Step 4, sew the second side of the zipper to the fabric. Make sure that the ¾-inch marks at the top of both pieces line up before you start sewing.
Step 7: Take a Peek
Oh dear, it looks rather twisted now, doesn’t it? Never fear. Simply zip the zipper and turn your work over to get a sneak peek at your invisible zipper.
Better? Good. Now, on to the next part.
Step 7: Finish the Seam Below the Zip
Return to the wrong side of your work. Moving the tail of your zipper out of the way, bring the fabric edges together at the seam allowance, and stitch the seam together.
Now turn your work over and finish the top.
That wasn’t so bad, was it?
All Zipped Up
Replacing a zipper isn’t difficult if you know how. Better yet, doing so can save you money, and save your favorite bag or garment.
Build your zipper replacement tool kit before you need it. Remember, you’ll need to be able to remove your old zipper, mark your fabric, pin a new zipper into place, and sew the new zipper in. You can often use a regular presser foot, but a special zipper foot can make your work easier, especially if you anticipate any tight stitching.
You might also find it helpful to have a few spare zippers of different lengths and gauges to hand.
Are you ready to fix your zipper? Let’s go!
- SBSZipper | How To Measure The Zipper Gauge Correctly | https://www.sbs-zipper.com/blog/how-to-measure-the-zipper-gauge-correctly/
- wikiHow Staff | How to Whipstitch | https://www.wikihow.com/Whipstitch
- Collins | Stay Stitching | https://www.collinsdictionary.com/dictionary/english/stay-stitching