How to Unshrink a Sweatshirt in 5 Steps
To unshrink a sweatshirt, soak it in lukewarm water mixed with hair conditioner or baby shampoo, press the water out, stretch it back toward its old size and let it dry flat: 5 steps and about an hour before it goes to dry. The soak relaxes the fibers so they can be pulled open again. It gives back some size, not all of it, and it works better on cotton than on polyester.
We embroider custom pet sweatshirts on Gildan Heavy Blend fleece, which is a cotton and polyester blend, so this guide also covers how blends and hoodies respond and what to do around an embroidered design.
Table of contents
Can you fix a shrunken sweatshirt?
Yes, you can often fix a shrunken sweatshirt partway, but you cannot fully reverse the shrinkage. Unilever’s laundry site Cleanipedia puts it plainly: you can’t actually unshrink clothes, but you can stretch them back into shape so they become wearable again (Cleanipedia).
The reason is in how knit fabric is made. According to Cotton Incorporated, cotton knits are very sensitive to the forces applied to them, and knit fabric is usually stretched in length during wet processing at the mill. That built-in stretch can come out later, and tumble drying without tension compresses the fabric and allows the most drying shrinkage (Cotton Incorporated, ISP 1009). A soak in conditioner lets you pull those compacted loops open again by hand.
None of the sources we checked gives a reliable figure for how much size comes back, so treat the soak as a way to win back some length and width, not a full size.
How do you unshrink a sweatshirt?
To unshrink a sweatshirt, follow these 5 steps. Amounts and times follow Bob Vila and Cleanipedia.
- Mix a lukewarm soak. Fill a sink or basin with lukewarm water and stir in about 1 tablespoon (15 ml) of gentle hair conditioner or baby shampoo per quart (about 1 liter) of water. The FTC’s Care Labeling Rule defines “cold” as water up to 86°F (30°C) and “warm” as 87–111°F (31–44°C) (16 CFR 423, Appendix A); we recommend the low end of warm, around 90°F (32°C): warm to the touch, never hot. Skip regular shampoo, which is made to clean rather than soften.
- Soak for 30 minutes. Push the sweatshirt under until it is fully wet and leave it for 30 minutes, or up to 1 hour for heavy cotton fleece. If the label shows more polyester than cotton, use 15–20 minutes, as in Cleanipedia’s method for synthetics.
- Press the water out without rinsing. Lift the sweatshirt out, let it drip for a minute and squeeze it gently with flat hands; do not wring it. Roll it in a large bath towel for 10–15 minutes so it ends up damp, not dripping. Leave the conditioner in the fabric for now, because it keeps the fibers pliable while you stretch.
- Stretch it one section at a time. On a second dry towel, grip opposite sides of one area, pull gently and hold for a few seconds. Work across the chest, then the length from shoulder to hem, then each sleeve from shoulder seam to wrist. Measure as you go against a sweatshirt that fits, or against the Gildan 18000 sweatshirt size chart: a size M is 22 in (56 cm) wide and 28 in (71 cm) long.
- Dry it flat with weights. Hold each stretched area in place with books or paperweights and let the sweatshirt air dry flat, without overhanging edges. Check it after an hour while it is still damp and stretch again any part that has pulled back. Keep it out of the dryer.
Go slowly in step 4. Bob Vila warns against tugging too hard: overstretching one area pulls the sweatshirt out of proportion.
Does it work on cotton, 50/50 fleece and polyester?
It works best on cotton, partly on 50/50 cotton and polyester fleece, and very little on polyester. Cotton absorbs a lot of water and swells in the wash, while polyester generally does not shrink in normal washing (Cleanipedia on polyester). Bob Vila adds that synthetics resist stretching.
| Fabric | Example | What to expect | Soak time |
|---|---|---|---|
| 100% cotton fleece or jersey | Cotton crewnecks | The most response; the fibers relax and stretch relatively easily | 30–60 minutes |
| 50/50 cotton and polyester | Gildan 18000 and 18500 in solid colors | Partial: the cotton half can relax, the polyester half mostly holds its shape | 30 minutes |
| 60% polyester, 40% cotton | Gildan 18000 and 18500 in heather colors | Likely less than 50/50; follow the method for synthetics | 15–20 minutes |
| 100% polyester fleece | Performance fleece | Little change; worth a try only if it shrank slightly | 15–20 minutes |
For mixed fabrics, Cleanipedia’s rule is to check the label and follow the method for the fiber with the higher percentage. The fiber content of a Gildan Heavy Blend sweatshirt depends on its color (Gildan), so read the label before you soak it. Our guide to choosing a custom pet embroidered sweatshirt compares the blanks.
How do you reverse shrink a hoodie?
To reverse shrink a hoodie, use the same 5 steps, with two changes for the hood and the ribbing. On a hoodie like the Gildan 18500, the hood is double-lined, so roll it in the towel along with the body; it holds water in two layers of fleece.
We recommend putting the stretching into the body and sleeves, not the cuffs and waistband, which on Gildan’s hoodie are 1×1 rib knit with spandex. Stretch the front on both sides of the pouch pocket rather than across it, and lay the hood flat beside the body while it dries. Which garment suits a pet design is covered in our guide to sweatshirt, hoodie or T-shirt for a portrait.
What changes when the sweatshirt is embroidered?
On an embroidered sweatshirt, stretch the fleece around the design, not the stitched area itself. The stitched panel and the backing behind it do not stretch like the fleece, so pulling across a pet portrait may pucker the fabric at its edges. Grip on either side of the design, set the weights beside it rather than on the stitches, and follow our guide on how to wash embroidered clothing for the stitched panel.
How do you keep a sweatshirt from shrinking again?
To keep a sweatshirt from shrinking again, wash it cold and keep it out of long dryer cycles, because tumbling shrinks knits even without heat. In a Cotton Incorporated test, a 100% cotton interlock knit shrank more than 20% after 45 minutes in a dryer with no heat, and dryers at 150°F (66°C) and 200°F (93°C) reached the same shrinkage in less time; the researchers advised tumbling knitted cotton for no more than 5 minutes, then hanging it to dry (Textile World).
A stretched sweatshirt is no longer at its fully relaxed size, so a hot wash or a long tumble can pull it back. Our guide on how to wash a sweatshirt or hoodie has the full routine for plain fleece, and the care guide above covers embroidered pieces.
Frequently asked questions
Do you need to rinse out the conditioner afterward?
Not before you stretch, because the conditioner keeps the fibers pliable while the sweatshirt dries. Once it is dry, Cleanipedia suggests a cold wash with no dryer, though the small amount left in should not cause a problem.
Can you unshrink a sweatshirt in the dryer?
No. Tumbling is what compacts a knit, with or without heat, so the dryer cannot reverse the change. Dry an unshrunk sweatshirt flat and keep it out of the dryer until its next normal wash.
Can you stretch only the sleeves or the length?
Yes. Soak the whole sweatshirt, then stretch only the area that came out short, for example from the shoulder seam to the wrist to lengthen a sleeve. Keep checking both sleeves against each other so they stay the same length.
How long does it take to unshrink a sweatshirt?
The soak takes 30 minutes to 1 hour, the towel roll 10–15 minutes and the stretching a few minutes more. The sweatshirt then air dries flat until it is completely dry.
