How to Wash a Swimsuit: 9 Care Tips to Make It Last

The fastest way to ruin a good swimsuit isn’t wearing it — it’s not knowing how to wash a swimsuit properly after you take it off. Spandex starts losing elasticity within hours of chlorine exposure, and the average bikini that’s tossed in a hot dryer with a load of towels loses up to 40% of its stretch in fewer than ten cycles. The good news: the rules are simple, and almost all of them take less than two minutes a day.

This guide walks through exactly how to wash a swimsuit the right way — rinse, hand wash, dry, store — using the routine swimwear engineers and dye chemists recommend, written in plain English instead of laundry-tag hieroglyphics. Follow it and a $40 set will outlast a $200 one that’s been microwaved through a hot wash and a tumble dryer.

Why How You Wash a Swimsuit Matters More Than the Brand

Modern swimwear is mostly nylon or polyester blended with 15–22% elastane (also sold as Lycra or spandex). That stretchy fiber is what hugs your curves — and it’s also the most chemically fragile thread in your wardrobe. Chlorine attacks the polyurethane segments inside elastane, which is why pool suits get baggy in the seat long before the print fades. Heat accelerates the same damage. Sunscreen and self-tanner add a second layer of staining most washing machines won’t touch.

So care isn’t a vanity step. It’s the difference between a suit that fits the same in August as it did in May, and one that sags after your fifth pool day. The actual swimwear brand matters far less than whether you do the next four minutes of work after you take it off.

Rinse First — The 30-Second Habit That Saves Your Bikini

Before anything else, rinse the suit in cool fresh water the moment you’re out of the pool or ocean. This is the single biggest decision in the whole care cycle. Salt crystals act like tiny knives inside the weave once they dry, and chlorine keeps eating the elastane every minute it stays in the fabric. A quick rinse under the beach shower or in the hotel sink stops both clocks immediately.

You don’t need soap yet. You don’t need a basin. Just hold the suit under running cool water and gently squeeze (don’t wring) until the water runs clear. If you’re at a public beach with no fresh water, a sealed bottle of drinking water poured over the suit is enough to prevent the worst of the salt damage on the trip home.

How to Wash a Swimsuit by Hand — The Right Way

Hand washing is the gold standard for any swimsuit you actually care about. Fill a clean sink or basin with cool water — never warm, never hot — and add about a teaspoon of mild detergent. Swimwear care guides and Persil’s fabric specialists both recommend a free-rinsing wool or delicates wash like Eucalan, Soak, or The Laundress Delicate Wash. Skip regular detergent — its enzymes and brighteners eat dyes and weaken the elastane fibers.

Submerge the suit, gently press it under the water, and let it soak for 10 to 15 minutes. Swirl it around with your fingers — don’t twist, don’t scrub. After the soak, drain the basin, refill with clean cool water, and rinse the suit by pressing it between your palms. Repeat the rinse once if the water still looks soapy. The whole process takes less than 20 minutes of mostly hands-off time.

Can You Put a Swimsuit in the Washing Machine?

Technically yes. Practically — only if you do it carefully. The machine isn’t the villain most laundry blogs make it out to be, but the heat, agitation, and metal hardware in a normal load absolutely are. If you’re going to use a machine, follow three rules: cold water only, delicates or hand-wash cycle, and the suit always goes inside a mesh lingerie bag. The bag stops underwires and clasps from snagging the elastane, and it also stops the suit from being whipped around the drum by jeans or towels.

Don’t add fabric softener — it coats the fibers and ruins the suit’s ability to wick water. Don’t bleach, ever, even color-safe bleach. And never, ever put a swimsuit in the dryer. The heat melts the elastane’s bonds and the tumble action stretches out the cups and elastic permanently. Air dry every time, no exceptions.

How to Remove Chlorine, Salt, and Sunscreen Stains

Chlorine smell is the most common complaint, and the most common mistake is trying to mask it with more detergent. Don’t. The smell is residual chlorine bonded to the fibers, and you need to dissolve it, not perfume it. Mix a tablespoon of white vinegar into a quart of cool water and soak the suit for ten minutes, then rinse thoroughly with fresh water. Vinegar is acidic enough to neutralize the chlorine without bleaching the dye.

Sunscreen and self-tanner are the toughest stains on white or pale fabrics. The avobenzone in chemical sunscreens reacts with iron in tap water and turns a rusty pink-brown — once it sets, it’s almost impossible to remove. The fix is speed: pre-treat the stain within 24 hours by rubbing a drop of mild liquid detergent directly into the spot, leaving it for 10 minutes, then hand washing as normal. For older sunscreen marks, an enzyme-free stain remover like Carbona Stain Devils #9 works on the oily residue without further attacking the spandex.

Salt is the easiest stain of the three — it’s water-soluble, so any cool-water rinse pulls it out. The damage from salt is structural, not visual, which is why beach suits that go unrinsed get crunchy and lose stretch even when they still look fine.

Drying Without Wrecking the Fabric

How you dry the suit determines whether it keeps its shape. The rules are short: lay flat, in shade, on a clean towel. Never hang a wet swimsuit by the straps — the weight of the water stretches the shoulder seams and elastic permanently, and you’ll see the cups start to droop within a few wears.

The technique most pro swimmers use: roll the wet suit in a dry bath towel and press gently to absorb water (don’t wring). Then lay the damp suit flat on a fresh dry towel, smooth out the elastic edges with your fingers, and leave it indoors or in shaded outdoor air. A bath towel on top of a drying rack works perfectly. Most suits are dry in two to four hours — far faster than your underwear because the fibers don’t absorb water, they shed it.

Direct sunlight is the second silent killer. UV breaks down dye molecules and weakens nylon at the same time, which is why suits that hang on a balcony rail all summer fade and feel papery by August. If you have no choice but to dry outside, flip the suit inside-out so the sun hits the lining instead of the print.

How to Store a Swimsuit Between Wears (and Off-Season)

Once the suit is completely dry — and that’s the key word, completely — fold it flat instead of stuffing it in a drawer. Mildew loves the dim, slightly damp corners of a beach bag, and a single overnight in a wet pile is enough to permanently stain pale fabrics. Cotton-lined drawers or breathable cloth pouches are ideal; sealed plastic bags trap residual moisture and encourage the same problem.

For off-season storage, don’t stack heavy items on top. Compression flattens the foam pads in molded cups, and that crease usually doesn’t recover. If your suit has removable cups, take them out and store them loose — they keep their shape better that way. A cedar block or two in the drawer keeps moths off if the suit has any cotton or wool content (some swim cover-ups and crochet tops do).

What Kills a Swimsuit Faster Than Anything

If you only avoid one thing, avoid hot tubs. The combination of high heat and concentrated chlorine or bromine is brutal — a single hour in a 102°F hot tub does more damage than ten ocean swims. SwimOutlet’s testing data shows competitive swimsuits losing roughly half their elasticity after about 25 hours of hot tub exposure, versus 200 hours of standard pool use. If you spend a lot of time in hot tubs, dedicate one cheap suit to it and keep your good ones for the pool and beach.

Other suit-killers worth knowing: sitting on rough concrete poolside (sandpaper for the lining), the powdered grip on yoga mats (clings and pulls), sunscreen mist sprayed directly onto the suit (concentrated chemicals on the print), and the rough textured benches in some saunas. None of these will end a suit immediately, but they cumulatively halve its life.

When to Replace a Swimsuit (and the Signs You Already Should)

Even a well-cared-for swimsuit has a finite life. For a suit worn weekly all summer, expect about two seasons before the elastane starts losing serious memory. Daily lap swimmers usually retire their suits at the 6-month mark. The signs the suit is finished: the leg openings or straps stay stretched out after a wash instead of springing back; you can see the lining through the outer fabric when dry; the cups have permanent dents; or the print has gone chalky and uneven.

One often-missed signal: if your suit feels noticeably looser at the start of the day than it did last summer, the elastane is gone even if the suit still looks fine. At that point new dye on tired fabric is just expensive Band-Aids. Time to shop.

Quick Fixes for a Tired Suit

A suit that’s losing its color but still has good stretch can be revived. Dylon and Rit both make polyester and nylon-rated dyes (regular cotton dye won’t take), and a hand-dye job runs about $8 and an hour of work. Stick to colors as dark or darker than the original — a black suit dyes back to crisp black easily, but a pink suit will not become navy.

For a suit that’s just starting to bag at the seat or under the cups, a quick cool-water rinse and a 5-minute soak in a 1:3 vinegar-to-water mix can tighten the elastane temporarily. It’s not a cure, but it can buy you another month of wear. For permanent shape loss, a tailor can take in seams for around $15–25 per pair — usually worth it on a designer suit, rarely worth it on a fast-fashion one.

A 9-Step Routine to Make Any Swimsuit Last

Here’s the whole care cycle in order — the fastest version you can actually follow on a beach day:

1. Rinse cool, immediately. The moment you’re out of the water, rinse the suit in cool fresh water — beach shower, hotel tap, water bottle. Don’t wait until you get home.
2. Hand wash within 24 hours. Cool water, mild delicates detergent, 10-minute soak. No twisting, no scrubbing.
3. Neutralize chlorine with a vinegar rinse. One tablespoon white vinegar in a quart of water; soak 10 minutes; rinse fresh.
4. Skip the dryer entirely. No heat, no tumble. Ever. This rule has no exceptions.
5. Roll-towel and lay flat. Roll the wet suit in a towel to absorb water, then lay it flat on a dry towel out of direct sun.
6. Never hang by the straps. Water weight stretches the elastic permanently.
7. Store fully dry. Fold flat in a breathable drawer or cloth pouch — never zipped in plastic.
8. Rotate suits. Elastane needs 24 hours to recover its shape between wears. Owning at least two suits doubles each one’s life.
9. Replace at the first sign of structural failure. Stretched leg openings, see-through fabric, chalky print — time for a new suit.

For more on building a swimwear collection that’s worth caring for, browse the athletic sporty bikini styles built for daily wear, the beach-to-bar cover ups that protect your suit from rough seating, or the tummy control picks engineered with denser fabric blends that hold up longer through regular washing. The right care routine, applied to the right suit, is what makes the difference between buying swimwear every season and building one you actually love for years.

Sources

1. The SwimSpot — The Do’s and Don’ts of Swimsuit Care — independent swimwear retailer’s guide to washing, drying, and storing performance and fashion suits.
2. Persil — How to Wash Swimwear — detergent maker’s fabric-care recommendations for elastane-blend swimsuits.
3. SwimOutlet — How to Make Your Swimsuit Last Longer — performance swimwear retailer’s testing data on elasticity loss in pool versus hot tub conditions.
4. The Spruce — How to Wash a Swimsuit Properly — practical step-by-step laundry method for hand- and machine-washing swimwear.