This is one of my favorite refashions: an upcycled swimsuit made out of a pair of pants. The straps can be styled as either off-the-shoulder sleeves, or cinched at the bottom and flared at the top of my shoulders.

I found the pants at one of my favorite local thrift stores, and I LOVED the fabric. It was totally my color, and it had kind of a streaky brushstroke look that reminded me of a Monet. But… I hated the fact that it was a pair of pants. I picked it up, and thought, “Someone needs to turn this into a swimdress.” And so I did.

The fabric, I should mention, was a polyester/spandex knit that was very stretchy. (You definitely don’t want to try this project with a pair of jeans.) It was also a very wide-legged pair of pants, and I still had almost no margin for error. If the pants had been a couple sizes smaller, I would have been in big trouble.

A pair of pants usually has four main pieces: left front, left back, right front, and right back. I cut the pants apart at the seams into these four sections. Next, I trimmed the waist end off of three of the pants sections, so that I was only working with the leg, and sewed the long edges of the 3 leg pieces together so that they formed a large, 3-panel tube. I kept the original hem of the pants, because there was no good reason not to.

I put the tube on like a dress, inside-out, orienting the seams so that I had 2 princess seams and one center back seam. Then I pinched the seams to see where I still had excess fabric, pinned the excess, and sewed where I had pinned so that the tube fit me the way that I wanted it to. (I did this while I was wearing it, but I’m using my dressform Vivian to demonstrate.)

I used a bra that I already had to add support and structure to the top, and made a pair of bikini bottoms (to wear under the dress) out of the leftover pants fabric.

A note about materials: Not every kind of elastic will hold up in chlorine or salt water, and therefore you’re not “supposed to” use a bra in a swimsuit if it’s not designed to be used in a swimsuit. But first, I was planning to mostly wear this swimdress in a freshwater lake. Second, the bra is not attached to the swimsuit, so I could swap it out if I ever needed to. And third, if you got a sewing handbook and looked up the proper materials to use for a swimsuit, they would likely NOT recommend using a pair of $4 thrift store pants of undetermined age and origin. In short, this was one of those times when I chose not to get too bogged down in the sewing “rules”, which is something you’ll also have to do if you’re going to make swimsuits out of pants.

The top edge of the dress and the leg openings of the bikini bottoms were finished with black swimwear elastic. This is a practical, easy way of adding elastic to swimsuit edges that keeps the fabric from stretching out and gaping, and it really makes a nice, clean finish. I have also used this edge finish on tank tops and other casual wear, even t-shirt necklines, and it holds up very well.

The waist edge of the bikini bottoms is just folded over and hemmed. I really didn’t want to use elastic on the upper edge, because I didn’t want the line from the top edge of the bikini bottoms showing through the dress. I did make sure that the vertical seams on the front of the bikini bottoms were on the outside, just in case I had to stitch them to the dress seam allowances to keep the bottoms from sliding down, but that hasn’t been necessary. I could also add elastic to the waist edge in the future.

The swimdress straps have pieces of poly featherboning in them, to hold the straps out in a wide flare at the top of my shoulders. I used 4 narrow scraps of the pants fabric to tie the dress straps to the bra straps. This was to cinch the straps in the front and back, which accentuated the flare of the sleeves at the top of my shoulders, and also so that the swimsuit couldn’t slide down when I had it styled as a cold-shoulder dress. They look like little bows on the straps, and I think they’re pretty cute.

The end result is a classy upcycled swimdress that I absolutely love!