How to Shrink a Bathing Suit to Get the Perfect Fit

how to shrink a bathing suit swimsuit

A sagging swimsuit is not a good look. No one wants to look like they are wearing a wet diaper, nor do they want to flash their private parts when they want to look decent. However, if the solution is to toss out the old one and fork out some cash for a new bathing suit, it might make some people want to wear their old swimsuit anyway. The good news is, those aren’t your only options.

For whatever reason, if your swimsuit is now saggy, you may be able to shrink it a bit so that it will fit snug on your body once again. And no, we aren’t about to tell you to break out your needle and thread because that’s difficult and there’s a much easier way to handle this problem.

Rather than get rid of a perfectly usable swimsuit or spending money on a new suit, you can apply one or more heat treatments – putting it in a dryer, in boiling water, or ironing it – to cause your old swimsuit to shrink. This way, you can potentially get more use out of your old bathing suit and not have to waste money buying a new one.

These methods are straightforward and can easily be done at home assuming you already have the appliances (chances are high that you do). Keep reading to learn the exact steps you need to perform to shrink your bathing suit so that it fits you perfectly once again.

How does heat shrink a swimsuit?

A terrible feeling that I wouldn’t wish on anyone is when you take your clothes out from a dryer and realize that they no longer fit. Say bye-bye to your favorite pants, shirt, dress, sweater, whatever; they don’t fit you anymore! But how does this phenomenon happen in the first place?

The materials most susceptible to shrinkage when exposed to heat are cotton and wool, but this also applies to any organic fibers. The non-sciencey layman’s explanation is that heat causes the fibers to constrict, and it appears to affect organic fibers more than synthetic ones.

A pure cotton garment, for example, would shrink more than a cotton-blend one since there is less cotton, and a cotton blend garment shrinks more than something made completely of synthetic fabrics like spandex or Lycra.

Natural vs. synthetic fabrics


Before you try any of the methods listed below, you must first figure out what your swimsuit is made out of. Depending on the material, you may not be able to use some of the methods we recommend. This is a good guide on what type of fabrics can withstand what temperatures.

As mentioned, natural fabrics like cotton and cotton blends are much easier to shrink than synthetic fabrics (e.g. spandex, polyester, nylon, and Lycra-based swimsuits). Pure cotton will shrink much better than cotton blends which means you need to be careful not to expose it to too much heat, otherwise it will shrink more than you want.

Synthetic fibers will also shrink when exposed to high temperatures, but you have to be careful for a different reason. Referring back to the guide we linked above, you’ll notice that synthetic fabrics have a limited maximum temperature range of 230 F (110 C), and the drying temperature should not exceed 180 F (82 C) otherwise they can get damaged.

When exposing your swimsuit to high temperatures, such as during a hot wash cycle, first turn it inside out to protect the color from fading. If done correctly, it should just take one heat treatment to shrink your bathing suit down to the right size.

Best ways to shrink a bathing suit

Take a look at your swimsuit label and read what it is made out of. Ignore the washing and drying instructions; what we are attempting to do is not recommended by the manufacturers, who obviously do not want to receive complaints from customers who accidentally shrunk their bathing suit. We are doing it on purpose, however, so it doesn’t apply to us.

The dryer


The first and most obvious solution is to shrink a bathing suit with the dryer. Everyone has first-hand experience with accidentally shrinking a bunch of clothing they did not intend to, but in this case it can be quite a useful “feature”.

Before you toss your suit into the dryer, there are some steps you have to take first. We highly recommend you turn the bathing suit inside out to preserve its color. Also, if there are any pads, remove them so that they don’t get deformed. You can easily put them back later.

Next, hand wash your bathing suit in cold water using a mild laundry detergent (should not contain any bleach) to get rid of any stains, dirt, or oil. If you were thinking you could skip this step by using a washing machine, don’t. The tossing and spinning motion of a washing machine can stretch and wear out your suit.

After washing the swimsuit, if it is still soaking wet, dry it by squeezing it between two dry towels. You can do this by laying a towel on the floor, putting the swimsuit on it, putting another towel over the swimsuit and first towel, and then stepping on it with your feet. Do NOT wring your suit dry as this can damage it and give it significant wear and tear. For the rest of this article, if we reference drying a soaking wet swimsuit, assume we mean with towels, not by wringing it.

Finally, we are ready to put the bathing suit into the dryer. Set the dryer to the highest heat setting and longest drying time. Make sure that the dryer is not too full or empty; too full and the swimsuit won’t get heated enough, too empty and the swimsuit will receive too much heat.

After the drying cycle is over, wait until it has cooled down to at least room temperature. Do not be in a rush to wear it as it could still be quite hot. Your swimsuit should have shrunk at least a little bit. If it has not shrunk enough, you can try repeating this method or try another of the heat treatments below.

Boiling water

boiling pot of water

If the dryer wasn’t enough to do the trick, you can combine it with our second method: putting the bathing suit in boiling water.

First, boil some water. The easiest way is to boil a large pot of hot water and you can just put the bathing suit directly in the pot once the water starts boiling. Otherwise, if you’re boiling water via a kettle or some other method, you will need to pour the hot water into a separate container afterwards to submerge the bathing suit in.

Once the water has boiled, turn off the heat and submerge the bathing suit in the hot water. The goal is not to keep the water continuously boiling, but to let the water naturally reduce in temperature over time. After about 20 minutes or when the water is hot enough for you to take out the bathing suit by hand, you can take it out and dry it using towels.

As mentioned, this step can be combined with the dryer method. You would perform this step after washing the swimsuit, but before putting it in the dryer. This gives the bathing suit two opportunities to be exposed to high heat, helping it shrink even more.



Thanks to its high temperature and direct application on the garment, an iron can effectively shrink a bathing suit.

Once again, some prep work is required. Hand wash the bathing suit in cold water using a mild laundry detergent. It is essential that you remove any stains before ironing, as the iron could make the stains permanent.

Dry the bathing suit using the towel trick we mentioned until most of the water has been removed. What you should have left is a clean, damp bathing suit, ready to be ironed.

Place the damp swimsuit over the ironing board and cover it with a cotton cloth. This thin layer keeps the iron from having direct contact with the bathing suit, yet will still allow plenty of heat to go through.

Next, set the iron to the lowest temperature setting. If you’re using a steam iron, you don’t need to spray extra water as the bathing suit should still be damp.

Start ironing the bathing suit from top to bottom. Press each section carefully until you see water vapors. Do not leave it on longer than that, as prolonged exposure can burn the fabric. After you have finished ironing one side, flip it to the other side and iron it evenly. Otherwise, one side may have shrunk more than the other when it’s all said and done.

You are finished ironing once all of the water has evaporated, and your bathing suit is completely dry. This can take some time, especially at the lowest temperature setting. You may bump it up to a medium temperature if you feel the lowest is too low. This process can take upwards of 20 minutes, so be patient.

Common mistakes beginners make are that they forget to put an extra layer over their swimsuit and expose it to direct contact with the iron, burning it. They may also not realize that all of the water has evaporated at a specific section and leave the iron there for too long instead of moving on.

If you have little to no experience ironing, it’s possible you could ruin your bathing suit. If you are not comfortable with ironing, try the other two methods described above.

Can I shrink a large swimsuit?

If your bathing suit is much too big for you now then there is a chance that you will not be able to shrink it down to your current size, but you can try.

What you need to do is to first soak the swimsuit in cold water for at least an hour. This helps soften the material and may make it more receptive to the methods described in the sections above. However, don’t be surprised if you need to buy a new swimsuit that is closer to your current size.

You can also try this on a burkini if it is too loose.

Can I shrink a swimsuit that is already misshapen?

Yes, you can try restoring it to its original shape by placing a towel in the dryer with it. The heat from the dryer may smooth out its wrinkles and cause it to look normal again. However, you may simply get a smaller version of the misshapen swimsuit back, not one that has returned to its original shape. It doesn’t hurt to try since it is already deformed in the first place.

Can I shrink a neoprene swimsuit?

You can shrink a neoprene suit by putting it in the dryer or washing it in warm water, though it’s generally recommended not to do so. Neoprene can easily be damaged by heat, and the tumbling action can contribute to the damage.

What happens is that the nitrogen gas trapped within the neoprene layers will start to shrink and disappear over time when exposed to high heat, causing the suit itself to also shrink.

However, there are some consequences to this besides the suit shrinking. With smaller and less bubbles, you are getting less insulation and positive buoyancy from your suit. This means that you will not be kept as warm while in the water, and you cannot rely on it as much to help you float.

While you can put a neoprene suit in the dryer, to avoid these downsides, the best practice is to hang the suit inside out on a drying rack in a well-ventilated area, away from direct sunlight, such as a closet.