Does Cold Water Shrink Clothes? Here's What to Know

There’s nothing quite as disappointing as pulling a sweater from the wash only to find that it has shrunk to child-like proportions. It’s a common laundry complaint—and one that’s often blamed on water temperature. But does washing clothes in cold water really shrink them? Understanding what really happens to the fabric in the wash is the key to keeping your clothes looking their best.

To demystify the process, we chatted with two laundry experts who explain whether cold water is to blame for shrinkage, what causes fibers to contract, and what you can do to prevent it. 

Cold Water's Effect on Clothes

While temperature can have an impact on clothing shrinkage, it is rarely the only factor. And no, it's not cold water that causes fabrics to shrink. In fact, cold water is generally considered the safest option for most garments, James Joun, co-founder of Rinse, says. It helps fibers to hold their shape. 

“The reason behind shrinkage, in most cases, is heat and mechanical agitation, especially during the drying process,” laundry expert Alicia Sokolowski says. 

What Really Makes Fabrics Shrink

Shrinking happens when a garment’s fibers move closer together (which causes the item to be smaller in size). This happens due to a combination of moisture, heat, and agitation during the washing process. Warm water can cause slight shrinkage in linen and cotton, but won’t generally affect synthetics. With hot water, natural fibers run the biggest risk of shrinking.

“Wool, in particular, is highly sensitive to washing conditions. It absorbs moisture, causing fibers to swell,” Joun says. “During washing, mechanical agitation combined with heat can rapidly expel this moisture, leading the fibers to shift, interlock, and contract. This not only results in shrinkage, but can also degrade the garment’s hand feel: transforming a soft, luxurious texture into a rougher finish.” 

Natural fibers like cotton behave similarly to wool. When they absorb water, their internal structure relaxes. And if heat follows, those swollen fibers contract as they dry, pulling the garment in on itself. Synthetics (think: polyester and nylon) are more stable because their long polymer chains don’t absorb water the same way. They don’t swell, and their structure resists the relaxation seen in natural fibers, which is why they’re less prone to the shrinkage everyone fears. But even synthetics aren’t immune to the effects of heat: excessive dryer temperatures can warp or distort them, even if they don’t technically shrink.

Another key factor? Manufacturing. Many fabrics are stretched during production, and, when exposed to heat, they relax back to their original state. “Water, heat, and movement allow the material to return toward its natural, lower-tension shape,” Sokolowski explains.

6 Ways to Prevent Fabric Shrinkage

Want to avoid shrinking your favorite sweater or most-worn blouse? Check out these helpful reminders from our experts:

• Read the care tags. “Some fabrics are pre-treated, while others require specific handling,” Sokolowski says. Reading the care tag will help you properly treat the item.
• Use cold water whenever possible. Sokolowski explains that cold water generally protects most fabrics and slows down fabric strain. Translation? Your garment will hold its shape for longer when you wash it in cold water. 
• Remove items slightly damp. “Allowing clothes to finish drying naturally helps prevent over-contraction,” Sokolowski says.
• Limit heat during the drying process. Both Sokolowski and Joun say that air drying clothes is the safest option. But if that's not possible, then Sokolowski recommends using a lower heat setting on the dryer. 
• Choose delicate cycles. Delicate cycles reduce the agitation on fabric, particularly with delicate wool and rayon pieces.
• Be extra careful with wool. “Wash in cold water, avoid agitation, and lay flat to dry to prevent both shrinking and distortion,” Sokolowski says.