How to turn a leggings pattern into Swim Jammers

Boy wearing swim jammers

Well, it’s fall here and for us, that means the start of a new season of swim team.

My son loves the water so this was a nice fit for him instead of more traditional sports. If you have children on a swim team, you know how expensive it can be. We bought his first few pairs of swim jammers and while nice, I got to thinking…aren’t they just leggings?

After a few attempts to get the fit right, I was in business!

I’d like to show you how to make your own swim jammers.

There are several pdf pattern companies that offer free leggings patterns. I chose to use the Made for Mermaids Bonny Leggings. These are nice because they come with several length options. I print off his size and tape it together. The pattern gives you waist and hip measurements to ensure you get the right size.

Start by adjusting the inseam.

My son likes the inseam on his jammers about nine inches so it sits just above the knee once hemmed.

Cut the pattern out now.

Next, let’s adjust the rise.

This pattern uses a separate waistband. Since I don’t want it separate, I simply add to the rise to accommodate the elastic I will be using. About midway through both the front and back rise, I draw a line and cut. Insert paper in between and increase about an inch.

If we were just making leggings, we’d be done, but because these are jammers and for a boy, we need a little more coverage. I took a look at his previously purchased pair and there’s a triangular shaped front crotch lining. I measured that and made up my own pattern piece similar in size.

Cut 2 mirror images of the jammers piece and 1 crotch lining panel.

I typically fold this piece in half and cut on fold, but you can do whichever suits you.

Serge the two crotch seams (front to front and back to back) right sides together.

Serge the long edges of the front crotch lining.

Line up the legs and pin or clip together.

This is where I add the bottom of the crotch lining piece. Mark the center of the crotch lining and pin it to the center of the front crotch on the jammers. Sew together up one leg and down the other.

Flip the front crotch panel up and pin to the waistband matching the center of the panel to the center of the front seam.

I like to use clear elastic because it doesn’t stretch as much and I’d prefer it if these didn’t fall down when my son dives into the pool. Attach to the wrong side of the waistband stretching slightly. I’ve found using the triple stretch stitch works best for me with a width of 5 and length of 2.

It’s hard to see clearly, but lightly stretch the clear elastic as you sew.

Fold waistband to the wrong side so elastic is covered and stitch again using the same stitch as before. I also like to add clear elastic to the legs. I use the same method as above, but don’t stretch while attaching.

That’s it!

You have a new pair of swim jammers at a fraction of the cost!

So, you’re a pro at making your kid awesome swim jammers, but now he sees the other kids with cooler ones because they aren’t all one fabric.

Let’s fix that!

First is easy, make each leg a different fabric! Just make sure you’re cutting mirror images or you’ll end up cutting more out. Easy, right?

What about fun stripes?

This does require a little more work, but you can get some really fun ones. Let me show you a couple variations I do. Take your original pattern piece and trace it. I like to use banner paper because it’s plenty wide for just about any project.

Now, start at the center back and measure down about 3 inches.

Remember you’re going to lose about 3/4 of an inch with the elastic waist, so it will be closer to 2 1/4 inches. If you want a bigger stripe, adjust that measurement now. I now mark the bottom of the leg where I want the back of the stripe to be. The back on mine hits about center.

Draw a line out from the back crotch line curving down to the bottom of the leg.

Take that first line and measure about 3 inches across from it the entire length. I like to hold a ruler all along the first line and mark periodically.

Cut along the lines so you now have 3 pieces.

Lay each piece down on your banner paper and trace.

Add 1/4 seam allowance to both sides of the center stripe and to the one side of the front and back piece where you cut the center stripe out.

Cut 2 mirror images of each pattern piece out of your fabric. I like the front and back to be solid and use a fun print for the stripe.

Pin the stripe piece to the front and back pattern pieces and serge.

Now you should have 2 pieces that look like your original!

Sew up same as before.

One more variation I like is a curved side stripe.

Do the same as before and trace your original piece.

Find the center of the side and measure 2 inches each direction and mark. Do this on the bottom of the leg too.

Now draw a curvy line or X shape from your top point to the bottom.


You can really get creative with this! Measure out 4 inches from your first line and draw a second line all the way down the side. You can make this more wide or narrow depending on your preference.

Cut your pieces apart.

Same as before, retrace your pieces and add in the 1/4 inch seam allowance to both sides of the center curved line and the coordinating front and back pieces.

Cut out two of each of the pattern pieces from fabric and one crotch lining piece.

Pin back together and serge.

Again, you should have 2 pieces that look like your original!

Sew up same as before.

There you have it!

Fun and funky swim jammers.

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What do you think about making your own swim jammers?  I’d love to hear your thoughts.

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4 thoughts on “How to turn a leggings pattern into Swim Jammers

  1. Thanks for this tutorial! Free pattern and scrap swim yielded me a pair for my 6-year-old who just started swim team. I’m excited to try a few more variations.
    Thank you again!

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