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How to Shrink Sweatpants

Sweatpants come in many styles but always offer a loose fit, a soft feel, and plenty of room for movement. But sometimes these comfy pants become too loose if they get old and stretched out, causing them to sag at the knees or the waist. You don’t need to throw away the baggy pants, though, because you can easily learn how to shrink your sweatpants!

The best way to shrink sweatpants is to use the hottest settings on the washer and dryer along with color-fast detergent to prevent fading. Other popular methods include using a boiling water bath for polyester pants. Spot treatments with an iron or a hairdryer can shrink certain areas of the sweats, like the waistband or knees.

In this article, you will learn six simple methods for shrinking sweatpants. You will find out how to shrink cotton fleece vs polyester sweats. Finally, you will discover tips for how to fix thick sweatpants or too-long sweatpants.

How to Shrink Sweatpants

Can You Shrink Sweatpants?

You can usually shrink sweatpants by at least one size by applying heat and moisture, but this does depend on the type of sweats to some degree. The style and kind of fabric in your pants make a big difference in determining how much the sweats can shrink.

But first, what exactly are sweatpants? Are they the same as yoga pants or leggings?

In most cases, the term “sweatpants” kind of loosely covers many styles of athleisure pants. People use the word “sweatpants” to cover everything from soft cotton knit yoga pants to silky nylon workout pants to cotton fleece elastic-waist sweats.

If you want to get more technical about it, though, sweatpants are loose pants made out of cotton fleece with either a drawstring waist or an elastic waistband. They can have cuffed ankles or loose, wide legs, or even come in a cropped leg.

This style of pants was invented in the 1920s for professional athletes to keep them warm during outdoor workouts. Of course, today, everyone loves the cozy comfort of this fleecy style of sweats!

The exception to this rule is nylon joggers, which are also almost universally known as sweatpants! In fact, you see the terms sweatpants and joggers used interchangeably by many fashion experts.

This makes a big difference because the kind of fabric in your pants can make them easier or harder to shrink. For example, 100% cotton sweats will shrink super easily. Traditionally, thick elastic-waist cotton fleece pants did contain 100% cotton.

But these days, cotton costs a lot to produce, so many clothing manufacturers have replaced all-natural cotton with synthetic polyester fleece. Polyester fleece sweatpants look and feel very much like cotton, but this man-made material does not shrink easily.

When it comes to slinky, loose-fitting joggers like the popular striped Adidas black and white pants, you may also need to deal with nylon.

The best way to find out what kind of material your pants are made out of is to find the small manufacturer’s label sewn into a seam in your pants. Typically, this label is placed at the center back of the waistband. It will tell you the fabric composition and useful care instructions for the garment.

Finally, the style of the pants also makes a difference. If you have pants with an elastic waist that has gone all saggy, the fabric itself may not be the issue. You may need to replace the elastic band inside the waistband.

But the type of fabric can cause your sweatpants to stretch out more easily, too. For instance, the cotton (or polyester) fleece that makes most sweatpants is made out of a knit fabric. This type of material uses loops of interconnected thread instead of crisscrossing threads in its weave. This makes it more stretchy than many kinds of material, leading to saggy knees or a loose waistband over time.

What Makes Clothes Shrink?

Three factors usually combine to make clothing shrink: heat, moisture, and friction. Unfortunately, your clothing encounters all three of those forces during a regular washing and drying laundry cycle! The good news is that you can use this to your advantage if you want to make your sweatpants smaller.

If you use hot water in your washing machine, the clothing experiences a sudden influx of moisture, heat, and friction as the machine agitates. If you then place those still-warm garments into the dryer, they get another intense dose of heat from the dryer, as well as added friction from the tumble dry action inside the machine.

While every kind of fabric reacts in slightly different ways to heat, moisture, and friction, most materials contain fibers that will contract under these conditions, making the garment smaller all over.

Cotton shrinks very easily when exposed to heat because the cotton spinning process puts a lot of strain on the cotton fibers. In high heat, the fibers relax and spring back into their natural, smaller state.

Polyester fibers do not react in the same way. This man-made material has pretty high heat resistance but can melt once it gets over that threshold. Simply putting polyester pants in the dryer should not shrink them, but you can achieve the same result by exposing the polyester to boiling water.

Of course, if you do not want to shrink your clothing, you should avoid heat as much as possible! Simply washing your clothing in cold water will alleviate many shrinking problems.

How to Shrink Sweatpants: 6 Methods

What Makes Clothes Shrink

You can shrink sweatpants using a washer and/or dryer or by using special spot treatments like applying a clothing steamer.

Since most sweatpants are made of stretchy knit material, they can easily stretch out or get baggy. You can choose any of these six simple methods to get them back into shape!

1. In the Washer

One of the absolute easiest ways to make your sweatpants shrink by as much as one size is to run them through the washing machine.

  1. First, check the settings on your machine. Make sure you select hot water. If you want to shrink your pants as much as possible, you can even add a hot-water soak before the washing cycle.
  2. Next, make sure you use a color-fast detergent. In some cases, your pants might fade in hot water without this special detergent.
  3. Set a timer for yourself, so you don’t miss the end of the washing cycle. You will want to immediately place your pants in the dryer before they can cool down from the hot water. Alternatively, if you only wanted to shrink your sweats by a little bit, take them out of the washer and spread them on a clean towel to air dry.
  4. Put your pants in the dryer or lay them out to air dry, and then try them on to see how much they shrunk!

You can always repeat this method all the way through if you find that pants did not get small enough. Remember that most clothing can only shrink by about one size, as the fibers can only expand and contract by so much!

2. In the Dryer

The dryer is one of your best options for easily shrinking clothing like cotton fleece sweatpants. It provides both heat and friction. In fact, for the absolute maximum of shrinking, you can use the washing machine method and then immediately follow it up with a cycle in the dryer!

You can also spritz your sweats with a spray bottle of clean water and then run them through a dryer cycle to get a more moderate amount of shrinkage.

Do you know how your jeans usually feel a bit snugger after you launder them? This happens because the cotton fibers have relaxed and contracted into their natural, corkscrew-like shape, making the whole garment smaller! The same thing will happen to sweatpants made of cotton when you put them in the dryer.

Sweatpants made out of polyester won’t shrink as much, but you may find that they get a little tighter after a cycle in the dryer.

Just make sure you check the settings on your machine before putting your sweats in. Options like “high heat” or “extended cycle” will shrink your clothing the most. Settings like “permanent press” delicates” or “synthetics” will apply a gentler heat that will not work as well.

3. Boiling Water

Boiling water reaches a temperature of 212℉, which can cause almost any type of fabric to shrink! This is an extreme method that does require some careful handling of very hot objects, but it is the only method that will consistently work on sweatpants made out of polyester.

  1. Find a large pot and make sure your pants can easily fit inside it. Remove the pants, and fill the pot about three-quarters full of water.
  2. Place the pot on your stovetop and bring the water to a boil over high heat. You can use a thermometer to test the water to find out when it reaches 212℉, but you will see frothing bubbles on its surface as well once it hits a rolling boil.
  3. Use salad tongs or grilling tools to carefully lower the pants into the water. Once you have poked all portions of the fabric under the water, remove the pot from the hot burner.
  4. Let the pants soak in the pot of hot water for 5-20 minutes. The longer they soak, the more they will shrink!
  5. Use potholders or dishtowels to carry the pot to a sink and dump it out. Do not touch the pants with your bare hands, as they will remain very hot.
  6. Once the pants cool down a little, squeeze them between your hands to press out some water. At this point, you can either use the dryer method for maximum shrinking or allow the pants to air dry if you do not want to shrink them a whole lot.

4. Steamer

A handheld-clothing steamer can apply targeted heat and moisture that can cause a small amount of shrinking at just the right places in your sweatpants. A clothing steamer will not apply a huge amount of heat, so this gentle method will not cause dramatic results. But if you notice that the knees in your pants always look saggy after a while, you may want to try this method!

  1. Set up your steamer according to the package instructions. For some steamers, you need close access to an electrical outlet. For others, you may need to use distilled water.
  2. Turn on your steamer and let it warm up. If it has setting options, select the hottest one.
  3. Hang your sweats up on a curtain rod or shower curtain rod so you can easily access them with the steamer.
  4. Once you see steam coming out of the nozzle, run the nozzle back and forth over the areas you want to target. Do not touch the fabric with the nozzle, but stay as close as you can to get the full impact of the steam.
  5. Keep moving the steamer back and forth over the target areas for several minutes.
  6. Turn off the steamer and put it in a safe place to cool down.
  7. Allow your pants to air dry on a flat surface, such as a clean bath towel.

5. With an Iron

Another way to target specific areas of your sweatpants is to use an iron. You need to take care with this method, though, as not all sweatpants can handle the heat. Check the manufacturer’s label inside your pants to see if you can safely use an iron on them or not.

You should not try this method on rayon, nylon, or polyester pants. You should also avoid ironing directly on any vinyl prints on your pants, such as a logo or decorate elements.

  1. Spread out your sweats on your ironing board. In a pinch, you can also set up on a flat surface like a kitchen table. Just spread some kind of padding such as a bath towel over the table first.
  2. Prepare your iron according to the instructions on the package. Many irons require distilled water in their steamer reservoir to avoid mineral buildup.
  3. Turn on your iron, set it to the hottest steam setting available, and wait till it indicates that it is heated up.
  4. Run the iron back and forth over the pants, moving slowly but constantly. This will allow the steam to infiltrate the fabric as you go.
  5. You can target key areas of the pants or iron over the whole garment.
  6. Once you finish on one side, turn the pants inside out and iron from the reverse side of the fabric as well.
  7. Let the pants cool down till they feel comfortable to the touch. Then try them on to see if they shrank enough. If not, try ironing again.

6. Fabric Softener

You can use fabric softener to help shrink your clothes in a couple of different ways. Fabric softener helps the fibers in your clothing relax, making them a tiny bit smaller. If you combine this property with a heat source, it can cause a fair bit of shrinking!

You can use this technique in two ways. First, you can add a fabric softener sheet to the dryer for the dryer method. This has the added benefit of helping you prevent static buildup in your clothes during laundering!

Second, you can mix a tablespoon of fabric softener in a spray bottle of warm water. Spritz this mixture thoroughly over certain areas of your sweats, like the knees or the waistband. Then dry that area complete with a hairdryer.

How Much Do Sweatpants Shrink?

How Much Do Sweatpants Shrink

In general, sweatpants will shrink no more than one full size in the washer or after trying any of the methods listed in this article.

Cotton sweats will shrink an average of 3% overall just from going through a regular laundering cycle. Polyester pants usually do not shrink much in a regular washing cycle. But they may shrink as much as one size if you try the boiling water method.

Shrinking clothes is a great idea if you love your sweats, they used to fit you, but they have gotten a bit worn out over the years. It is not such a great idea if you accidentally bought the pants four sizes too big–you almost certainly will not get them to shrink four sizes!

How to Shrink Sweatpants that Are Too Big

You can shrink sweatpants that are too big by up to one full size using heat and moisture, such as a hot water washing machine cycle followed by a spin in the dryer on high heat. These tips will help you handle special kinds of sweatpants that feel a bit too big for you.

Cotton Sweatpants

Cotton sweatpants shrink more easily than pants made out of almost any other material. You can use any of the methods in this article on this kind of pants, though you should read the tips below before starting!

These pants usually feature a smooth, knitted fabric on the exterior of the garment and soft fuzzy fleece on the inside. Brands like Nike and Champion sell multiple styles of sweats made out of this cotton fleece.

Check out these tips for shrinking cotton sweatpants:

  • First, check the label inside your pants to find out the exact fabric composition. Sometimes pants that look like cotton fleece feature 100% polyester!
  • Cotton can shrink a lot quickly. For this reason, you may want to set a five-minute timer if you use the dryer method. This way, you can periodically check on the pants and avoid shrinking them too much.
  • Cotton stretches out quite easily, so you may want to focus on the particular areas of the pants that have gone saggy. For this, try the ironing or steaming methods. Cotton pants can handle the what of the iron, so this is a great option to try!

Thick Sweatpants

Thick sweatpants may require extended soaking or heating times, but in all others ways, you can shrink them in the same way as you would regular-weight pants.

Some sweatpants come in heavyweight or 18 oz cotton fleece. This fabric often contains a blend of cotton and polyester fibers, making it slightly harder to shrink than 100% cotton pants.

  • You can still use your washer and dryer on thick sweatpants. But you may need to repeat the process two or even three times before you see significant shrinking.
  • To use the iron method, try slowly ironing each leg of the pants for five minutes. You will need to spend more time on this process for the heat to affect the thicker material.
  • If you have heavyweight sweatpants made entirely of polyester, your best bet is to try the boiling water method. The pants will get quite heavy as they become waterlogged, though, so handle them with care!

How to Make Sweatpants Tighter Without Sewing

You can make your sweatpants tighter without sewing using several methods, including inserting new elastic or shrinking elastic cuffs.

Around the Waist

Often, sweatpants have an elastic or drawstring waist that gets worn out and starts to sag or gap annoyingly. Elastic fibers eventually lose their elasticity after too much exposure to heat, which means that after you wash your pants a certain number of times, they no longer feel stretchy!

You can fix this problem without sewing in two ways. First, you can put in a new, longer drawstring and tie it more tightly. This will cinch in the waist, even if the fabric itself does not shrink.

Second, you can replace the elastic in some kinds of pants.

  1. Cut a neat incision at the inside back of the waistband. You should see the elastic inside after you do this.
  2. Snip through the wide elastic strip inside, and pull it out.
  3. Use a safety pin on the end of a new strip of elastic to work it back inside the waistband.
  4. Make a circle around the whole waist. When you have both ends of the elastic at the incision, use the pin to hold them together, closing the elastic circle.

Of course, this is a quick fix and you could also sew the elastic ends together if you prefer!

Around the Ankles

Another area where sweatpants can easily stretch out and get too loose is in the ankles.

One popular style of sweatpants, called joggers, has tapered legs and elastic knit cuffs at the ankle. If these cuffs get all droopy and saggy, you look like you’re wearing your big brother’s pants! No one wants that, so you may want to consider this easy hack to temporarily solve the problem.

  1. First, fill a small glass bowl with boiling water. Dip the cuffs into the water and let them sit for five minutes.
  2. Smooth out the hot, wet cuffs on a clean towel and squish them into the shape you want. For example, if the bottom of the cuff has become wider than the top, set it in a straight line.
  3. Next, blot off some of the moisture with another clean towel.
  4. Finally, use a hairdryer to dry the cuffs and set them in that smaller shape.


You can shrink sweatpants using a washer and dryer, your iron and ironing board, a clothes steamer, or even fabric softener! Cotton pants will shrink easily using any of these methods, but you will want to keep a sharp eye on them, so they do not over-shrink. Polyester pants may require a soak in boiling water to shrink a significant amount.

Most sweatpants contain cotton fleece with a knit surface that will shrink very easily when exposed to heat and moisture. You can often shrink this kind of sweats up to one full size.

Have you ever tried to shrink a pair of sweatpants? Did it work? Leave a comment below to let us know!