How to Sew a Flat Front Elastic Back Waistband on Low Rise Pants

I altered my exposed zipper pants from low-rise to high waist. I did this by adding a flat front elastic back waistband.

These pants really had no waistband and hung down too low, practically on my hip bones. But I’ve had them for a long time and wanted to keep wearing them.

You might also have some pants in your closet that could use a refashion. In my tutorial, I’ll tell you about the materials I used and how I did it step-by-step. 

Materials

These are the things you’ll need. Also, you’ll want to use the suggested fabrics and notions on the pattern that you choose.

• Pants pattern
• Fabric
• Zipper: I used a 7” metal zipper
• Elastic
• Interfacing: I used medium-weight fusible
• Basic sewing supplies: needles, thread, pins, scissors, iron, etc.

Notes on Choosing a Pants Pattern

If your pants are already made, then you’re all set. Most likely, you’re coming to this post because you want to add a waistband or make it thicker.

For reference, I used Simplicity S2665 sewing pattern to make my pants a long time ago. It doesn’t have a waistband per se, but had twill tape and a facing instead.

The pants have an exposed zipper and are darted in the back. They also have patch pockets and are very cute.

Notes on Choosing Elastic

I used 1-1/2 inch (1.5 inch) wide woven heavy stretch knit elastic for the back waistband. 1-1/4 inch (1.25 inch) wide elastic would work too. 

I was on the fence about using woven elastic, but the heavy stretch knit was my preferred choice. It was perfect for this project, giving it enough hold and stretch.

How to Add a Flat Front Elastic Back Waistband to Pants

This is an intermediate to advanced project. You’ll want to have experience with installing zippers and making pattern changes. If you’re not there just yet, you can save this for future ideas.

I’m focusing on only the waistband part in this tutorial, but you can see my other post on these pants for my other modifications. 

Note that I used a 5/8 inch (0.625-inch) seam allowance throughout.

1. Deconstruct the pants waist.

The first thing I did was deconstruct the waist area using a seam ripper. I originally made these pants with a facing and twill tape. You won’t need that for the waistband.

Also, I removed the zipper, and sorry, you’ll have to reinstall it. My original pants also had belt loops, and I took those off too.

When done, you’ll want to clean it up by cutting off any fraying.

2. Remove the darts.

My pants had darts in the back, and if you decide to make a fitted waistband, keep your darts. But I removed mine because I knew I’d add elastic, so they wouldn’t be needed.

3. Press the pants.

Now you’ll want to use your iron and press the area you’ve deconstructed. Make sure it’s nice and flat. 

We’ll be able to measure and see all the fabric we’re working with.

4. Make the back waistband.

Here’s the part you’ll have to play around with. Now, I suggest making a mockup of the waistband so you can test it.

Then baste it on the pants to check the fit.

To make cutting the band easier, you could grab another sewing pattern to use as a template like I did. If you don’t have one, you can use my measurements as a reference.

For a size 14, I started with a rectangle that was 25 inches by 4-1/2 inches (4.5 inches). 

Now, add as much as you need to make it long enough for the back width of the pants. So this requires measuring it across, and including the seam allowances too. 

Ultimately, you’ll want your waistband and pants side seams to line up. 

As you can see, I had to sew up some smaller pieces of fabric to make mine. 

5. Make the front waistband.

Although the back waist is a rectangle, my front waistband is contoured. So, you’ll see the slight curve.

Again, I grabbed another sewing pattern yoke to use as a template. This is the same process I used to make my flat front elastic back skirt hack.

I copied the yoke on tracing paper and then smoothed out the curve a bit. I made sure it’d fit with the rectangle, or back waist. 

In the end, you need to consider the seam allowances. They’re at the side seam and at the front zipper. 

The easiest way for me to do this was to make the front waistband one long piece. I planned to cut it later.

Remember, you’ll need to make a facing too, so cut 2 of the waistband. At this point, you’ll want to add interfacing to the front facing. 

6. Sew the front waistband.

Now you’ll want to sew the front waistband to the facing. Place right sides together and sew at the top along the seam allowance.

Then I understitched to keep it in place. Press them at the top.

After that, I cut it down the center front. I did this because I plan to reinstall the zipper in the front. 

If you plan to have a side zipper, there’s no need to cut it in the front.

7. Sew the front and back together.

I pinned the front and back waistbands together, making sure they fit in width. If your front waist is thicker, you may need to trim it down.

Next, I sewed the front and back waistbands together at the sides. 

You might notice how ragged my interfacing looks. And that’s because my iron was too hot, so it melted!

Then I basted the seam allowances down, as it makes it easier to pull the elastic through later.

You’ll end up with one continuous waistband from left front to right front.

Then I folded them over horizontally, and you can baste or pin in place.

8. Sew the waistband to the pants.

I pinned the waistband to the right side of the pants. Make sure the right and left ends match the pants correctly.

Although I checked that the side seams lined up in the above steps, I basted first to make sure.

Note that since this waistband will have elastic in the back, I made the seam allowance outside of the casing. 

I didn’t want the bulk inside the casing, as this was a heavier fabric. 

You might also want to finish the ends like I did with a zig-zag stitch or serger, since they’ll be exposed.

Leave an opening in front of the side seam to pull the elastic through. 

9. Press the waistband.

Next, I took that seam allowance and pressed it down with my iron. By the way, I hope you’ve been pressing while sewing this whole time!

Now we’re ready to secure the waistband in place.

10. Topstitch the waistband.

At this point, I topstitched around the waistband. You’ll especially want to do this with heavier fabric, as it’ll keep this area nice and tidy.

I find it easier to topstitch before adding the elastic, as there’ll be gathers. But some people like to do this after. 

Just remember to leave that opening clear to pull the elastic.

11. Sew the zipper.

Now it’s time to install the zipper, and you should still have your seam allowance for it. Remember, mine is exposed and in the center front of the pants. 

You don’t have to expose yours. Making it lapped or centered is also a good option. 

Note that I had to adjust the seam at the end of the zipper stop. Because of the higher waist, I moved the zipper up, so I had to close up the open part. 

12. Insert the elastic.

I used a bodkin to pull the elastic through one opening. Pull it through across the back and out the other side opening, creating the gather. 

I used a safety pin and pinned through the fabric and elastic near the side seams.

You’ll want to fit your waistband by trying on your pants. I do this before cutting the elastic, as I try to save as much as I can.

Make sure you have at least 1/2 inch (0.5 inch) overlap on each side. I actually give myself 1 inch in case I want to adjust later.

13. Secure the elastic.

After fitting the waistband, I stitched slightly near the seam line. While you can stitch in the ditch, I didn’t do that here.

I find that it’s difficult to undo if I need to adjust the elastic later. No one notices if you match your thread color.

After this, you can remove the basting along the side seam allowance. I always forget to do this until later!

I also made some tacks on the center back waist to keep the elastic from rolling. If using knit elastic, I recommend doing this.

14. Sew up the openings.

Now it’s time to sew up those openings on the waistband seam. After that, I continued my topstitching in that area too.

15. Finish the zipper.

For a finishing touch, I’ll hand-sew the zipper seam allowance, catching it to the waistband.

When you have heavier fabric, this helps keep it in place.

Sometimes I add a hook and eye at the very top. I didn’t this time, and this zipper locks very well.

Voila! Whew! And there you have it. All done!

Project Notes

Keep in mind that making the waistband is just one part of fitting pants. I also made other adjustments to the crotch length and leg width on my original pants. 

Adding the waistband may change the fit, so be aware of that. In my case, it made them way more comfortable.

Although I usually make a mockup, I didn’t make one for this project. I’ve made this waistband quite a few times for this pants pattern and knew what to expect.

Final Thoughts

I really love how my waistband refashion turned out. I can continue to wear my pants, and they fit so much better.

Sewing a flat front elastic back waistband on pants might be a challenging project. But once you get it down, you might comfy hacks on all of your pants!

More Sewing Projects

I have other related posts on my blog. You might want to check them out.

• Find out more about my exposed zipper pants and other changes I made.

• I’ll also show you how to do a flat front elastic back skirt waistband hack with a side zipper. 

• I made a denim mini skirt and hacked the waistband, with a centered zipper in the back.

• If you’re trying to decide on the best waistband elastic to use for a comfy fit, I’ll tell you. 

I’d love to hear all about your sewing journey!

Originally published: October 21, 2025