Nothing spells the start of Summer like the first dip in the ocean or pool. Make your little girl a DIY bikini bottom to start celebrating in style. This free bikini bottom pattern and tutorial will help beginners get their first taste of sewing stretchy swimwear and leotards. It doesn’t take much fabric so you can experiment and practice until you feel confident to tackle your first complete project.
DIY Bikini Bottom for Girls:
This free bikini bottom pattern for girls comes in sizes 2 to 14. There is a full sizing chart in the pattern so you can get a great fit.
You will need Lycra or Spandex fabric with at least 75% stretch. If you are not sure how to measure stretch factor make sure you get my printable chart to take with you to the fabric shop. Those of you who are not near any fabric shops should consider buying online: Where to buy lycra and spandex
- Main fabric – Sizes 2 to 7 need 3/8 yard (0.25m) and sizes 8 to 14 need 1/2 yard (0.45m)
- Optional swimwear lining – 13″ x 15″ (35cm x 40cm). This usually comes in flesh or black and is great for preserving modesty and giving a professional finish to your bikini bottom.
3/8 inch swimwear elastic. Sizes 2-5 will need 1 yard (0.90m) and sizes 6-14 will need 1 1/4 yards (1.10m). The exact cutting instructions are contained within the pattern.
Shop Sewing Patterns by Treasurie
Make sure you choose a good brand of swimwear elastic that is chlorine and sweat resistant. (Read different types of elastic.) Don’t choose a cheap overly stretchy elastic as you won’t get good results.
Download Your DIY Bikini Bottom Pattern
By now you are probably getting excited and asking so where do I download my pattern? Click on the link below to get the pattern absolutely free. Just add it to your cart and checkout. Don’t worry, you won’t be asked for any credit details for any free items.
How to Make a DIY Bikini Bottom – Instructions
Step 1- Crotch Seam
Put the front and back together with RIGHT sides facing together and match the raw edges at the crotch. Stitch across with either your serger or regular sewing machine. If you are using a regular machine don’t forget to use a stretch needle to prevent skipped stitches. (Read how to sew Spandex and Lycra with a regular machine for extra tips on getting nice stitching.)
Step 2 – Lining
Lay your bikini bottom on your worktable with the BACK wrong side facing up. Place the lining on top of the BACK matching the raw edges of the crotch. Swimwear lining usually doesn’t have a right or wrong side but if it does it should be wrong side facing up.
Stitch across the crotch through all 3 layers.
It may seem a little strange to be stitching the lining to the back but you will be flipping it forwards in the next step. All will be revealed!
Flip the lining to the front so the crotch seam is hidden. Baste the front to the front lining all the way around the edge. A simple straight stitch will do as this stitching will be hidden in the construction.
Step 3 – Side Seams
Fold the pants with the RIGHT sides together and stitch the side seams with a 1/4 inch (6mm) seam allowance.
I used a narrow zig-zag ( width 1 and length 2.5) and then did a wider zig-zag on the edge (width 4 and length 2.0) to strengthen the seam.
Further Reading: How to Sew Lycra
Step 4 – Elastic
I have a separate tutorial on how to sew elastic in the legs since there are a few steps involved. You will use the same method for both the waist and the legs. Read the full article: How to sew elastic in leotards and swimwear
Here is a YouTube video I made for you showing how to sew the elastic in the free bikini bottom pattern. Relax, grab a coffee and enjoy! Don’t forget to subscribe for more videos.
To summarize the elastic steps, you will:
- Mark the leg holes and waist in quarters.
- Stitch the elastic in a loop and mark that in quarters.
- Match the quarter marks of the legs or waist and zig-zag through the center of the elastic.
- Turn the elastic in to form a hem and zig-zag over the edge.
Hooray! You are done:
All finished and ready to hit the water!
I hope you enjoyed this free sewing pattern. Don’t forget to sew a top to wear with the bikini bottom!