Our most-requested swim style ever! Perfect for teens who want fuller coverage in the front and back—while being fully protected on their period. Wear it alone on light days, or with a tampon or menstrual cup on heavy days.
Layer 1: A silky-smooth top layer that sits comfortably against the skin.
Layer 2: A highly-absorbent middle layer designed with our leakproof technology to absorb about the same as 2-3 super tampons worth of period blood.
Layer 3: A waterproof outer layer prevents swelling.
Other Features:
- Bum coverage: Max
- Wide waistband for comfort
- Mesh interior lining
- Super discreet liner
- 50+ UPF protection
- Pair with matching Double Scoop Bikini Top
Our most-requested swim style ever! Perfect for teens who want fuller coverage in the front and back—while being fully protected on their period. Wear it alone on light days, or with a tampon or menstrual cup on heavy days.
Layer 1: A silky-smooth top layer that sits comfortably against the skin.
Layer 2: A highly-absorbent middle layer designed with our leakproof technology to absorb about the same as 2-3 super tampons worth of period blood.
Layer 3: A waterproof outer layer prevents swelling.
Other Features:
- Bum coverage: Max
- Wide waistband for comfort
- Mesh interior lining
- Super discreet liner
- 50+ UPF protection
- Pair with matching Double Scoop Bikini Top
Machine wash cold and lay flat to dry. Do not bleach, iron, or dry clean.
Body: 85% Nylon, 15% Spandex
Lining: 85% Nylon, 15% Spandex
Gusset: Leakproof Technology®, Polyurethane Film
For items with a 20% or more discount, you may exchange for another item or return for store credit. No refunds can be accommodated.
Items marked as “Flash Sale” or “Clearance” are final sale, meaning no returns, exchanges or refunds can be accommodated. No exceptions.
Please note: Sale items are not eligible for our First Pair Risk-Free Policy.
We offer free standard shipping on all orders over $70. We ship our items via DHL or Canada Post depending on your location. Please allow 1-2 business days for your items to be processed and shipped. During high volume periods, your order may take up to 7 business days to dispatch from our warehouse location.
US Orders: Please allow 3–10 business days for orders to arrive.
International Orders: Please allow 10–25 business days for orders to arrive.
NOTE: Orders placed on Friday after 1 PM will not be processed until the following Monday.
CANADIAN CUSTOMERS: Shop www.knixteen.ca to order in Canadian currency.
Our period swim bottoms contain a triple-layer gusset that absorbs your flow and locks in leaks, whether you're in or out of the water. When they go in the wash with detergent, the blood releases through the top layer—leaving your swimwear fresh and clean for next time. Yes, your other clothes will remain stain-free!
Here's the breakdown of our 3-layer leakproof technology:
Layer 1: A silky-smooth top layer that sits comfortably against the skin.
Layer 2: A highly-absorbent middle layer designed with our leakproof technology to absorb up to 1-3 tampons worth of period blood.
Layer 3: A waterproof outer layer prevents swelling.
Not always. When your flow is light, our swimwear can be worn alone without any additional period protection. On super heavy days, we recommend wearing a tampon or menstrual cup with your swimwear. Every period is different though, and we recommend doing whatever makes you feel most confident.
Machine wash cold and lay flat to dry. Do not bleach, iron, or dry clean.
Check out our size chart here.
Yes! All of our regular price swim bottoms and one-pieces are eligible for a return or exchange within 30 days of delivery, as long as the original sanitary strip and tags are attached. Our swim tops are eligible for a return or exchange within 30 days of delivery with original tags attached.
Absolutely! The leakproof liner built into all of our period swimwear is undetectable, so they look and feel just like regular swimwear.
Our styles are made to fit teen bodies. For period swimwear in adult sizes, please visit Knix.
Perfect
| Comfort |
Rated 5 out of 5
|
|---|---|
| Fit |
Rated 0 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True to Size and 2 is Runs Large
|
| Effectiveness |
Rated 5 out of 5
|
| Ease of Use |
Rated 5 out of 5
|
I liked the look of these online so decided to get the teen swim shorts even though I’m a 42 year old mom. I am very happy I did! I usually wear a size small in Knix clothing so I sized up to Medium in these. They are really flattering and super comfy! The gusset doesn’t feel uncomfortable or bunchy. Great product and incredibly fast shipping!
My daughter feels so comfortable in these and true to size. She's happy that she can enjoy pool days!
The size lge fit my 11 1/2 year old daughter just right. She has worn them twice and they have done the job so far.
I bought these on a whim, not even knowing if my daughter would ever end up using them. Well, a couple weeks later, her period came the exact day we were going to go swimming so having them ended up working out perfectly. She had no leaks and could play comfortably all afternoon!
She’s 11, tall and slim and I usually buy her an XS in the underwear but since she’s right at the cusp of sizing up, I went for a Small so it should fit her next year too.
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.Still Not Sure What Size To Get?
| KT Size | Band | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|---|
| XXS | 23 3/4" - 25 1/4" | 25” - 27” | 7 | --- |
| XS | 25 1/4" - 26 3/4" | 28” - 30” | 8 - 10 | --- |
| S | 26 3/4" - 28 1/4" | 31" - 34" | 12 - 14 | 00 - 2 |
| M | 28 1/4" - 29 3/4" | 35” - 38" | 16 - 20 | 4 - 8 |
| L | 29 3/4" - 31 1/2" | 39” - 42” | --- | 10 - 14 |
| XL | 31 1/2" - 33 1/2" | 43” - 46” | --- | 16 - 18 |
| XXL | 33 1/2" - 35 1/2" | 47” - 50” | --- | 20 - 22 |
1. Band
First, measure around the torso right below the breast
2. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Still Not Sure What Size To Get?
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Still Not Sure What Size To Get?
| KT Size | Band | Hips |
|---|---|---|
| XS | 28" | 25” - 27” |
| S | 30" | 28” - 30” |
| M | 32" | 31” - 35” |
| L | 34" | 36” - 40” |
| XL | 36" | 41” - 44” |
| XXL | 38" | 45” - 48” |
1. Band
First, measure around the torso right below the breast
2. Hips
KT Leotards are designed to sit on the hips, so measure around the widest part of the hips and refer to the chart above to find the best fit.
Still Not Sure What Size To Get?
| Size | Bust | Hips |
|---|---|---|
| XS | 27” | 25" - 27" |
| S | 30” | 28" - 30" |
| M | 34" | 31" - 35" |
| L | 37” | 36" - 40" |
| XL | 40” | 41" - 44" |
| XXL | 40” | 45" - 48" |
Still Not Sure What Size To Get?
| Size | Hips | Height | Weight |
|---|---|---|---|
| XS/S | 25" - 30" | 4'2" - 5'1" | 65 - 100 lbs |
| M/L | 31" - 40" | 4'9" - 5'6" | 105 - 130 lbs | XL/XXL | 41" - 48" | 4'11" - 5'6" | 135 - 170 lbs |
Still Not Sure What Size To Get?
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.Still Not Sure What Size To Get?
