Don't let a loose, oversized sports cap ruin your enjoyment of the game -- custom-fitted hats are so-named for a reason. Through regular exposure to sweat and sun over time, they'll shrink down to your size, but if you can't wait that long for a comfortable fit or bought a hat that's a whole size larger than your head, a little extra heat can go a long way.
100 Percent Wool and Cotton Caps
Wool and cotton fibers shrink naturally when wet and dried and conform to whatever shape they're given, so use your own head like a hat block to get a custom fit.
Small Size Change
Fill a spray bottle with warm water and spritz the inside headband to dampen it.
Wear the hat outdoors, in the sun, until it dries completely, or direct a hair dryer on a medium setting toward the wet areas.
Large Size Change
Dampen the inside of the crown of the hat with a garment steamer or the steam from a pot of boiling water. Dry the crown with a hair dryer. Repeat as many times as is necessary to shrink the hat.
If there is no risk of color bleed from logos or the brim, take a hot shower while wearing the hat. Dry the hat with a hair dryer after the shower and smooth out any wrinkles with your fingers.
Never put a fitted hat in the dryer. This may fade the colors, wrinkle the fabric and warp the bill.
100 Percent Polyester Caps
Some fitted hats are made from polyester instead of wool or cotton. Unfortunately, polyester does not shrink unless subjected to extremely high heat, which can damage hats. Steaming and drying the crown repeatedly or soaking it in hot water may have some effect.
Heat exposure may also do nothing. Some polyester fabrics have already been preshrunk in high heat scenarios, and will not respond at all to further heat shrinking methods. You may be stuck with the hat size you have.
Cotton/Polyester Blend Caps
Cotton/poly blends shrink somewhat less than 100 percent cotton caps, depending upon the ratio of cotton to polyester. If a cap is 80 percent polyester and 20 percent cotton, you may only be able to shrink the hat a small amount. The larger the cotton percentage, the more easily you can change the hat size.
Shrink cotton/polyester blends just as you would a 100 percent wool or cotton cap. Hot water, rather than warm water, may be more successful if the polyester percentage is high.