How to make a one piece swimsuit

Make a beginner friendly, simple one-piece swimsuit with this free PDF sewing pattern. 

Simple One is a comfortable  swimsuit pattern from size 36 to size 52.

It is designed for 4-way stretch swimsuit fabric like Lycra, stretch polyester featuring a crosswise and lengthwise stretch of 50%. 

This sewing pattern is designed to add a 4-way stretch lining at the front and back. You can leave out the back lining if you prefer, but be aware of transparency.

Choose the best size according to your measurements.

To better adapt to all different heights, this pattern has two different versions in all sizes.  The difference is the length of the pieces.  Before you begin printing your pattern, please consider how high you are.

swimsuit size guide

For the best result, first do a fit test using an inexpensive fabric.

Make sure everything’s okay. Make modifications if necessary and cut your precious fabric when you are satisfied with the result. 

Don’t worry! No one’s got the standard sizes. Look at me. I’ve got size 38 in the bust, but 40 on the waist and hips. I use size 38 because it is a stretch  enough to cover these extra centimeters at the hip.

If you are between two sizes choose the smaller one, the stretch fabric will allow it to stretch a few centimeters. If the difference is larger than one size consider adding a few centimeters more where it is needed.

Note that elastics will make you feel your swimsuit more fitted. Don’t worry if it is gaping at the armholes or other parts before adding elastics.

This free pattern is available with instructions in English or Spanish. Choose what’s best for you.

swimsuit pattern by height

One piece swimsuit pattern free

How to make a DIY swimsuit

See what others made

Get inspired

Want to see fellow sewists wearing their finished Simple One one-piece swimsuit? Check out this post on Instagram as a result of collaboration with the wonderful online sewing community #CosidoresMallorca.



printed fabrics by yard

Fabric Suggestions

Sport Lycra from Soonflower

Wondering what kind of fabric you use for your hand-made swimsuit? I made my swimsuits with Spoonflower’s Sports Lycra. I love this fabric, as it is strong, but stretchy enough and keeps its colors alive after having used them for several years. Head to my Spoonflower shop to select the print that you like.


swimsuit classes on Skillshare

Learn how to sew swimwear

Are you insecure about sewing the swimsuit with all those complicated elastics? 

Don’t worry! Check out the last, ninth lesson in my course: Design, Sew, Swim, where I’ll show you step by step how to sew the Simple One swimsuit. (When you download the free pattern, you will be given access to view the course for free.)

Free Workshop

Do you prefer bikinis?

Do you like bikinis instead of swimsuits or both? Why not learn how to hack the free swimsuit pattern to create bikinis?Learn how to transform the free one piece swimsuit pattern into three different bikinis or even a sports bra.