My kids are really into swim shorties these days and I ain’t complaining. They’re super quick and easy to sew, and don’t take up much fabric. Old me surely would have spent way too much time browsing pattern group companies, looking for a “swim shorties” specific pattern. Fortunately, present me has grown confident enough in pattern usage and versatility, that I often dip into my preowned pattern vault for stuff I can mod before buying something new.
Swim shorties honestly don’t require any special pattern marketed as such. For my son, I traced an old pair of sleep short/brief things we had at home from GAP and made my own pattern. If you understand the basic construction steps of making shorts, that’s a super easy way to make them. For my daughter, I used the shorties from the Cami, Undies, and Shorts pattern* from Ellie and Mac. I construct them for my son and daughter the same way, and I’m gonna show you exactly how now! All you’ll need is whatever your fabric requirement is for the shorts plus the same amount in swim lining, and a piece of 3/4″ or 1″ elastic for the waist.
The pattern I am using comes with the option to attach elastic or add a fabric waistband. For the purposes of this tutorial, I am using the higher rise (for adding elastic). If your pattern only has a waistband option, you can attach that after you’re done with the shorts or you can add double your elastic height to the top portion of your pattern pieces to increase the rise and account for the elastic being attached and folded over.
Go ahead and cut your fabric for the shorts, and cut another set in swim liner. To get started sewing, Place a mirrored front and back together and sew the outseam and the inseam Right Sides Together. Note: The liner looks smaller than the swim fabric, but that’s simply the angle the photo was taken. It’s the same size 😉
Turn one of the shorts leg Right Side Out and leave the other Wrong Side Out. Insert the one that is Right Side Out into the Wrong Side Out one with Right Sides Together. Align the raw edges and sew the crotch curve. Repeat these same steps with your Liner fabric.
You will now have what looks like two sets of shorts. Turn the main Right Side Out and the Liner Wrong Side Out. Insert the Liner into the main, aligning all raw edges around the waist and leg openings. This will enclose the seams from both pairs of shorts to the inside. I like to baste the waistline together or use lots of clips to hold the layers together before attaching the waistband, as I find that helps me get things done more evenly. I also like to finish the hem with my serger so that it’s easier to hem the two layers of fabric. These are both optional.
Now decide on the elastic measurement. If your pattern already includes this, you can cut to that measurement. I personally like to wrap the elastic around the waist of the wearer and cut. Either way, overlap the two ends of your elastic and sew to form a loop. Divide the waistband and the elastic into four equal parts. Place the elastic inside of the shorts up, aligning the raw edges and pin or clip together, matching up your pins or clips from before. Make sure to add as many as you need, and stretch the elastic to fit, but do not stretch your shorts! Sew the elastic to the edge with a serger or zigzag stitch, then fold the elastic toward the Liner and topstitch in place with a coverstitch or other stretch stitch. Finish up your hem and your shorts are ready!!
These stay up very well on my daughter in and out of the water and she was a fan of the extra coverage. I paired it with a rash guard for her birthday beach trip this year and she loved it so much!