Jeans shrink easily when you wash them in hot water or dry them in an automatic dryer on high heat. A common way to stretch jeans that have shrunk slightly is to put them on and do squats or lunges. Another way is to spray cold water on the jeans while wearing them, and stretch them out when the jeans are wet.
For jeans that have shrunk so severely that these common methods fail, however, the bathtub stretching method described below will stretch the tightest of jeans.
Spread out about an 8-foot length of dry bath towels on your bathroom floor or down a hallway near your bathroom to keep your floor dry in Step 6.
Fill the bathtub with warm (not hot) water. Fill to a depth that would cover your legs if you were to sit in the tub.
Put your jeans on. Even if they are tight, squeeze them on and try to zip them up.
Get into the bathtub wearing your jeans, and soak for 15 minutes. This will be slightly uncomfortable.
Drain the bathwater. Stand up and squeeze out some water by running your hands down the sides of your jeans.
Do 10 to 15 lunges over the dry towels. This will stretch the jeans further. The towels will help keep your floor dry.
Take off the jeans and hang them to dry over a shower curtain rod or on a dryer rack.
If your jeans did not shrink much, put on the jeans and do lunges when the jeans are dry. Sleep in your jeans to loosen them.
Do not dry jeans in dryer. They will shrink.