Do Swimsuits Shrink or Stretch?

As an Amazon Associate we earn from qualifying purchases.

Most manufacturers make swimsuits from tight materials that can stretch to give you a comfortable fit. When you purchase a swimsuit you might wonder if you need a bigger size in case the suit shrinks or a smaller size if it stretches out over time. However, before settling on a decision, you’d need to know the answer to this question: do swimsuits shrink or stretch?

Do Swimsuits Shrink or Stretch?

Swimsuits actually tend to stretch over time. A swimsuit stretches out because the elastane loses its elasticity and will no longer snap back to its original shape. Certain nylon swimsuits will stretch less, but all swimwear stretch over time. As a result, you definitely don’t want to buy a loose fitting suit, because it will only get looser over time!

a woman lying on the beach wearing swimsuit

Why Do Swimsuits Lose Elasticity?

A swimsuit loses its elasticity because the elastic fibers break down and become weak. The elastic fibers in any article of clothing will eventually stretch out and become loose-fitting. However, the elasticity in a swimsuit is more susceptible to stretching out quicker because of a few aspects such as:

  • Chlorine
  • Washing machines
  • Bleach and laundry detergent
  • Dryers
  • Hang drying
  • Wringing or twisting
  • Sunlight


Chlorine is a chemical in pools and hot tubs that keeps the water clean. What you might not know, is that it can ruin your swimsuit over time. Chlorine breaks down the elastic fibers and can fade the color in swimsuits. If you’ve ever had a white bathing suit turn yellow, chlorine is the reason why. 

Even though polyester fabric is chlorine-resistant, it won’t prevent the chlorine from breaking down the elastane in your swimsuit. The only way to avoid this is to either avoid chlorine or switch up swimsuits so they can last longer. 

Washing Methods

You should almost never use a washing machine to clean your swimsuit. A swimsuit is often small and full of thin strings. This makes it easy to get tied around other clothes in the washer which means it was being stretched a lot between clothes.

The best way to wash your suit is to hand wash it with cold water. The most important thing to do is to rinse your swimsuit in cold water right after you’ve taken it off. This will get rid of some of the chlorine and sunblock that’s been soaked into your suit. 

Make sure to avoid hard scrubbing while hand washing your swimsuit and never use bleach or laundry detergent. Instead, use a mild hand soap that will be gentle on the fabric.

If you would like to wash your swimsuit in the washing machine, always use cold water and use a delicate detergent. It helps to add it to a small load of clothes to prevent the suit from getting tied around other garments. Or, you can purchase a mesh laundry bag to place your swimsuit in while in the washer.

Drying Methods

Never use the dryer to dry your swimsuit! This is something you should always try to avoid. The heat of the dryer will cause the elastic fibers to break down causing it to lose its strength.

Air drying your swimsuit is a much better option that won’t stretch out your suit. However, do not hang your swimsuit while it’s wet. This can pull down on the elastane in the swimsuit and weaken it over time. Instead, place it on a towel and leave it to dry.

Make sure to avoid the sunlight when drying. It’s better to let your swimsuit dry indoors in a warm environment, rather than in the sun. UV rays from the sun break down the fabric in the swimsuit and can even allow the color to fade. 

Another thing to keep in mind is not to wring out or twist your suit after washing. This can also stretch out your suit. Squeeze the water out and if it’s still dripping, once you place it on the towel, roll the towel with the swimsuit, squeeze it and then unroll and leave to dry. 

a sexy woman wearing swimsuit sitting beside a boat

Should I Buy a Swimsuit in a Size Smaller or Should I Size Up?

Because a swimsuit can stretch over time you shouldn’t buy a swimsuit in a size smaller. This can, in fact, stretch your swimsuit out sooner because it will have to stretch to fit your body each time you put it on. Not to mention, a smaller suit can give you an unflattering fit. 

Sizing up isn’t a good idea either. Getting a size up in bathing suits won’t prevent the swimsuit from stretching over time. It’s true that it won’t have to stretch to fit you, though, other aspects such as chemicals in pool water and sunlight will ruin the elasticity over time. So if you get a bigger size, you’ll be left with an even larger suit after you’ve worn it out. 

It’s always best to stick with your correct size when buying your swimwear. A smaller suit can create bulges and a larger swimsuit can leave you with a saggy bottom and not enough support in the chest.

Reasons Why Swimsuits Stretch

ReasonsWhat causes the stretch
Reason 1Chlorine in pools and hot tubs
Reason 2Washing using machines, bleach and detergents
Reason 3Drying using dryers or hang drying
Reason 4Wringing and twisting
Reason 5Drying in direct sunlight

Frequently Asked Questions

How Can I Shrink a Swimsuit?

You can shrink a swimsuit by putting it in hot water and putting it in the hot cycle of the dryer. Alternatively, you can iron your swimsuit using low heat settings when it’s still moist after washing.

Keeping in mind that most swimsuits are made of polyester fabric which is primarily made with polymer, heat makes them shrink.

Can an Overstretched Swimsuit Come Off When Swimming?

There are minimal chances of the swimsuit completely coming off when swimming, even if it’s over stretched and loose.

However, keeping in mind that some swimsuits, such as thong bikinis, have minimal coverage that only covers the genitals, overstretching can make the fabric loose when swimming, revealing your private parts.

Why Is My Swimsuit Disintegrating?

The main reason why swimsuits disintegrate is due to chlorine added to the swimming water. Generally, chlorine is a strong chemical that can make the fabric of the swimsuit fade, lose elasticity, and ultimately disintegrate.

That means there are higher chances of the swimsuit falling apart if you swim in public pools and spas.

100 Years of Bikinis | Glamour


Swimsuits are often made with durability in mind to withstand these harsh conditions and prevent it from stretching out. Though, depending on how you care for your swimsuit and how much you wear it can determine how long the elasticity lasts. If you follow the advice listed above, you’ll be able to keep your swimsuit from stretching out for a long time!