Learn How to Translate a Bra Pattern Into a DIY Swimsuit Top

Liz Sews
by Liz Sews
3 Materials
4 Hours

This tutorial is one that I get requests for all the time: how do I turn a bra pattern into a swimsuit pattern? Many of us have spent years finding a bra pattern that is perfect for us. One that fits just right and provides the support we’re looking for, making us feel confident and pretty. So why can’t a swimsuit do the same? I’ll show you how I took one of my favorite bra patterns and converted it into the perfect swimsuit top!

Tools and Materials

Tools and Materials:

  • Rubber elastic
  • Swimsuit fabric
  • Clasp
Add extra seam allowance
Add extra seam allowance

For bras, we tend to let the elastic show on the inside of the bra. With swimsuits, we need to cover it. This means that you will need to add an extra seam allowance to this part of the pattern. Make sure that you adjust it according to the width of your elastic.

Use rubber elastic
Use rubber elastic

For swimwear, I highly suggest you use an all-rubber elastic. It will hold up better and longer than other elastics. 

DIY swimsuit elastic

It comes in a variety of widths, so determine which is best for you.

Adjust the pattern for the closure
Adjust the pattern for the closure

The biggest alteration to the bra pattern comes in the back of the pattern. I wanted a t-back for the swimsuit top, so I needed to make the necessary adjustments. I adjusted the pattern accordingly, making sure that the bottom seam allowance matched the elastic and changing the shape of the back piece.

Check that this works well with the closure you’re using as well as the width of your elastic.

Swimsuit fabric

Obviously, one of the main differences will be the fabric. Make sure to use swimwear fabric if possible, however, polyester/spandex fabric should work as well. 

The back closure
The back closure

As the back closure will be visible on the finished swimsuit, I chose to use this clasp which adds a touch of professionalism to the finished look. You can of course go with a large g-hook if you prefer.

DIY swimsuit top

These are the main changes that need to be made to the original bra pattern. For the full tutorial check out my video above!

Suggested materials:
  • Rubber elastic
  • Swimsuit fabric
  • Clasp

The author may collect a small share of sales from the links on this page.

Join the conversation
2 of 3 comments
  • Maureen Cassidy Maureen Cassidy on Dec 16, 2021

    Hi Liz

    I just found this Upstyle blog and decided to use it to reach out to you. It was a pretty big shock to see your YT videos ‘gone’. They are what got me into making bras…you are THE BEST teacher out there. Stumbled onto the critique that pushed you to pulling your videos….I chose to not comment as it would only add total negativity and malice towards the initiator of that post.

    I LOVE your videos! Is there a way to perhaps put them on a Patreon channel and those that care to use them, pay your subscription price for access?

    I for one would definitely be overjoyed to use them…you are a wealth of knowledge and communicate it extremely well. If you care to reach me, my email address is: mcassidy8@cox.net

    Thank you for all your time, effort and knowledge. I am staying positive!🥰