Do Swimsuits Stretch or Shrink in Water?

When you're buying a swimsuit, one of the main things you're probably concerned about is fit. How well a suit fits is the most important aspect when it comes to your comfort and overall happiness with the suit. An ill-fitting suit makes a day at the beach a nightmare.

Another concern is longevity. Stretching, along with exposure to direct sunlight, salt, sand, and chlorine, is one of the fastest ways a swimsuit wears out. The way your bathing suit fabric responds to water - whether it stretches or shrinks - could determine how long you get to wear the suit for.

So, Do Swimsuits Stretch or Shrink in Water?

All swimsuits naturally loosen a bit in the water, regardless of the water type. The weight of the excess water naturally makes the fabric heavier, meaning it will pull down and away from your body. They will also stretch out through use and movement. A suit that was snug in May will lose its original shape by September if you swim in it daily.

For this reason, it's important to choose a suit that fits snugly, especially if you will be wearing it a lot, or wearing it for high-energy activities like swimming or surfing. Your suit should be a little on the tight side when dry. In fact, it should almost compressive. If you can squeeze into it and aren't spilling out, you're good to go.

Obviously, make sure the suit is still comfortable; that it isn't riding up and that you're not in danger of popping out of it. But a saggy suit on land runs a high risk of coming off completely in the water (check out our in-depth sizing chart to ensure you have the right size suit before purchasing!)

How Different Swimsuit Fabrics Respond to Water

You should also take into consideration the type of fabric your suit is made of, and how different fabric types responds to cold water, hot water, salt water, chlorine, laundry detergent, etc. Swimsuit care is one of the main factors that determines longevity, so make sure the way you're washing your suit is right for the fabric.

Polyester Swimsuits

Polyester is a commonly used synthetic fiber that holds up well against chlorine. It's light, durable, and holds its original shape better than other synthetic fabrics like lycra. A 100% polyester swimsuit will be less likely to stretch in cold water, and will be less damaged by chlorinated water.

Unfortunately, polyester swimsuits tend to be less comfortable than other swimwear fabrics.

Lycra

A 100% lycra swimsuit is extremely flexible and comfortable but, unfortunately, breaks down very quickly in chlorinated water or salt water. This makes it a poor choice if you swim in pools regularly. With daily use in a chlorinated pool, a lycra swimsuit will last only 4-5 weeks!

One way to increase the chlorine resistance of lycra swimsuits is to make sure you always rinse it with cool water after swimming. Don't let the chlorine or salt sit for too long in the suit, and especially don't let the suit dry with chlorinated water in it.

Nylon

Nylon gives you the best of both worlds when it comes to synthetic fabrics: it's chlorine-resistant like polyester but flexible like lycra. It holds up well against chlorinated water, making it a good choice for swimmers who spend a lot of time in pools.

Natural Fibers

Swimsuits made from 100% natural fibers like cotton, hemp, or bamboo react slightly differently to chlorine and salt, but they still stretch in water because of their weight, just like any other fiber. Natural swimsuits may require slightly different care to avoid shrinkage - such as washing in cold water only, or use very mild detergent.

How to Care for Your Suit

No matter what type of swimsuit you choose, following a few basic care tips can extend its life.

Rinse With Cool Water

Always try to rinse off with cool, fresh water after getting out of the pool or the ocean. Rinsing out the salt, sunscreen, chlorine is the number one way to extend the life of your suit. A great way to do it is to simply run it under a cool tap, then gently squeeze out the excess water (don't wring! This will stretch the fibers and can cause the suit to sag.)

Minimize Direct Sunlight

UV rays break down swimsuit fibers almost as quickly as salt and chlorine do. If you want to keep your suits looking like new, don't lay them out to dry in the sun. Store them in a cool, dark, well-ventilated place when you're not using them.

Hang Dry

Unless the label says, you should avoid putting swimsuits in the dryer. This can shrink your suit faster than anything—although if you're trying to salvage a stretched-out suit, it might be a tactic to try!

How to Decide What’s Right for You

The best suit for you is the one that makes you look and feel the best. Your comfort is the most important thing, so if a suit feels uncomfortably tight, go for the next size up. Choose fabrics that fit your lifestyle and budget, and don't feel pressured to adhere to trends if they don't make sense for your body.