How to Get Sweat Stains Out of a Hat

To clean sweat stains out of a hat, scrub the sweatband and the stained line with a mild cleaner and a soft brush, let the cleaner sit for a couple of minutes on stubborn spots, then wipe it off with a damp cloth and air dry on a form. Most fresh sweat stains come out in one or two rounds.

Knowing how to clean a sweaty hat early saves a lot of scrubbing later. The older and crustier the stain, the more patience it takes. Below is the full process for yellow sweat lines, white salt rings, and that general sweaty-hat funk.

The quick answer

1. Dry brush the sweatband and the stained area to break up surface salt.
2. Put a little mild cleaner on a soft brush.
3. Scrub the sweatband along its full length, then work the stain line on the outside of the crown.
4. Let the cleaner sit 2 to 3 minutes on stubborn spots, then brush again.
5. Wipe away the suds with a damp cloth. Repeat once if needed.
6. Air dry on a rolled towel, then deodorize the band once it’s fully dry.

Why hats get sweat stains

Sweat is mostly water with salt and a bit of protein mixed in. Add skin oil and sunscreen, and you get a film that soaks into the sweatband and creeps up into the crown. When the water dries, the salt and oil stay behind.

That’s why you see two kinds of stains:

• White salt lines. Usually on darker hats. They’re dried salt sitting near the surface, and they come out pretty easily.
• Yellow or brown lines. Usually on lighter hats. That’s oil and sweat that have oxidized over time. These take more work.

What you’ll need

• A soft-bristle brush or old toothbrush
• A mild cleaner. Hat foam, or a few drops of gentle dish soap in a cup of cool water. Dish soap is good at cutting skin oil.
• Two microfiber cloths
• A rolled towel or ball for drying
• A fabric deodorizer (optional, for the smell)

How to clean sweat stains out of a hat, step by step

1. Brush it dry

Brush the band and any white lines while the hat is dry. Salt crystals break up and a lot of them just fall off. You’ll see the line fade a bit before you even get it wet.

2. Work the sweatband first

Fold the sweatband out so you can reach it. Put cleaner on the brush and scrub along the whole band with short back-and-forth strokes. Medium pressure is fine here since the band is tougher than the outside fabric. Pay extra attention to the front of the band, where your forehead sweats most.

3. Treat the stain line on the crown

Sweat often wicks up past the band and leaves a ring on the outside. Scrub that line lightly in small circles. Use less pressure than you did on the band so you don’t fuzz the fabric.

4. Let it sit

For yellow lines that didn’t budge, add a bit more cleaner and leave it for 2 to 3 minutes. That gives it time to loosen the oil. Then brush again.

5. Wipe, check, repeat

Wipe everything off with a damp cloth. Rinse the cloth and wipe again until no suds come up. Look at the stain in good light. If it’s lighter but still there, do one more round instead of scrubbing harder.

6. Dry it right

Stuff the crown with a rolled towel so it keeps its shape. Air dry somewhere with airflow and no direct sun for 4 to 8 hours. Don’t judge the result until it’s fully dry, since damp fabric always looks darker.

Still stained? Try this

The line is lighter but still visible. That’s normal for old stains. Two or three gentle rounds over a couple of days usually does more than one hard session.

It’s a white hat with a yellow band. Avoid chlorine bleach, which can yellow some white fabrics even more. An oxygen-based cleaner can help, but spot test it somewhere hidden first. Our white hat guide has the details.

The stain is set into a dark hat as a white crust. Brush it dry, then wipe with a cloth dampened in plain cool water before you use any cleaner. Salt dissolves in water, so sometimes that’s all it needs.

It’s been years. Some stains on very old hats have permanently changed the fabric color. You can usually make them lighter, but not always gone. Go easy on vintage caps and see how to clean a vintage hat.

Don’t do this

• Chlorine bleach. It can turn white fabric yellow and weakens fibers.
• Hot water. Heat can set protein stains and shrink the hat.
• Soaking the whole hat. It spreads the stain and can wreck the brim.
• A stiff brush on the crown. It pills the fabric and makes the stain area look worse.
• Drying it in the sun to “bleach” it. Sun can fade color unevenly, so you swap a sweat line for a faded patch.

How to get rid of the sweaty smell

The smell lives in the same place as the stain, so cleaning the band takes care of most of it. Once the hat is completely dry, mist the inside of the band with a fabric deodorizer. If it still smells, the band probably needs another clean. More tips in how to get the smell out of a hat.

How to keep sweat stains from coming back

• Wipe the sweatband with a damp cloth after hot days or workouts.
• Let the hat dry on a form after you sweat in it, not crumpled in a gym bag.
• Do a quick band clean every week or two in summer.
• Use a fabric protector spray on a clean, dry hat so sweat and dirt have a harder time soaking in.

If you run or golf in your hat, our performance hat guide covers the synthetic fabrics those caps use.

FAQ

How do you get yellow sweat stains out of a hat?

Scrub the band and stain line with a mild cleaner and soft brush, let it sit a few minutes, then wipe and repeat. Old yellow stains often need two or three rounds.

How do you get salt stains out of a hat?

Brush the white lines while dry, then wipe with a cloth dampened in cool water. Salt dissolves easily, so a light clean usually takes care of it.

Does baking soda remove sweat stains from hats?

Some people use a baking soda paste on the band. It can help with smell, but it’s gritty, so use it gently and wipe it out fully. Test it on a hidden spot first.

Can you clean hat sweat out without washing the whole hat?

Yes. Most of the time you only need to clean the sweatband and the stain line. That’s quicker and easier on the hat than a full wash.