Free Swim Trunks Sewing Pattern • Heather Handmade

Learn how to make a swimsuit for kids with a free swim trunks sewing pattern. This easy sewing project is for babies, toddlers, and kids!

It’s time for summer and swimming! I have made lots of swim trunks for my kids at different ages and sizes, and I’ve finally perfected my free swim trunks sewing pattern so that I can share it with you.

This is a beginner friendly sewing pattern since it’s just an elastic waist. The elastic waist is easier to sew and comfortable to wear. My kids don’t care if it’s a flat waistband or a elastic waist, and the added bow drawstring keeps the swim trunks looking cool.

What fabric should I use to make swim trunks?

Whenever I make swim trunks I use a woven microfiber fabric or boardshort fabric. The only online shops I’ve found this type of fabric is Raspberry Creek Fabrics and the Fabric Fairy.

I have also cut apart adult swim trunks to use the fabric, and that worked very well.

What sizes does the pattern come in?

The pattern comes in sizes 3 mos to 10. The baby and toddler sizes, 3 mos to 18 mos, are just trunks with no lining, and the child sizes, 2 to 10, have both trunks and a lining.

This tutorial shows how to make the swim trunks with the lining. If you are make a pair of swim trunks without the lining, you can just skip those steps.

What is a PDF sewing pattern?

A PDF pattern is a sewing pattern designed on the computer and organized so that it can be printed on several letter or A4 size pieces of paper.

I love using PDF sewing patterns because if the pattern gets ruined or if my children or I changed sizes, I can always print it again. It’ll never be destroyed since I have a digital version!

How do you use a PDF sewing pattern?

Open the PDF on a computer and click print. When printing make sure that the scaling is set to 100% or no scaling so that the pattern prints at the correct size.

Once the pattern is printed it can be taped together to get the full size. Then the pattern can be cut for each pattern piece size or individual sizes can be traced so that the pattern can be used again and again. Learn how to use PDF sewing patterns.

Do you love to sew? Try some of these fun sewing projects:

How to Sew Swim Trunks

Supplies

Free swim trunks sewing pattern – get it at the end of the post
3/4 yard of board short fabric
1/2 yard of swim lining (lightweight tricot or mesh)
1 yard of 1/4 inch elastic
1 yard of 1 inch elastic
Sewing tools
Sewing machine

Do you just want the pattern and tutorial as a PDF? Get the pattern and illustrated tutorial for just $6. You won’t need to access the internet every time you want to make it. Or get the Pattern Bundle with ALL the PDF tutorials!

Elastic Cut Chart

Cut out two mirrored swim trunks from boardshort fabric. Cut out one lining piece on the fold from swim lining fabric.

Place the trunk pieces right sides together matching up all the edges. Sew the center front and the center back with a 3/8 inch seam allowance.

Backstitch when you start and when you finish. Finish the edges with a zigzag stitch or a serger.

Line up the inseam with right sides together. Sew the inseam with a 3/8 inch seam allowance.

Backstitch when you start and when you finish. Finish the edges with a zigzag stitch or a serger.

Turn the swim trunks right side out. Fold the leg hems up 1/2 inch. Fold them up another 1/2 inch. Sew the hems in place 3/8 inch from the edge.

Line up the lining sides right sides together. Sew the side seams with a 1/4 inch seam allowance with either a zigzag or a serger.

Cut two pieces of 1/4 inch elastic using the elastic cut chart. Overlap the short ends of one piece 1/2 inch and zigzag in place. Do the same to the other piece.

Divide each loop into 4 equal sections. Divide each lining leg opening into 4 equal sections. Match each section of the elastic to a section of the leg opening. Pin the elastic along the edge of the wrong side of the leg opening. Zigzag the elastic into place. You will need to stretch the elastic to fit the fabric as you sew.

Do the same to the other leg.

Fold the elastic and fabric over towards the wrong side so that the elastic is fully enclosed. Zigzag the elastic in place. Do the same to the other side.

Place the lining inside the shorts with wrong sides facing each other. The right side of the lining will be against the skin of your child.

Pin the top edge of the lining 3/4 inch down from the top edge of the swim trunks. Sew the top edge of lining to the swim trunks.

Cut the 1 inch elastic according to the elastic cut chart. Overlap the ends by 1/2 inch and zigzag together.

Divide the elastic into four sections. Divide the top edge of the swim trunks into four sections. Match up each section of the elastic with a section of the swim trunks. Pin the elastic edge to the top edge of the swim trunks.

Sew the elastic in place with a zigzag stitch. You will need to stretch the elastic to fit the swim trunks while you sew.

Fold the elastic and edge of the fabric over so that the elastic is enclosed between the fabric layers. Zigzag the waist in place. Stretch the elastic to fit the fabric as you sew.