Most bathing suits can be machine-washed on a cold, delicate cycle in a mesh bag — but only when the care label permits it, since heat and agitation break down spandex.
Chlorine, salt, and sunscreen residue quietly eat away at the elastic fibers in swimwear, and a suit that gets tossed in with towels on a warm cycle will lose its stretch within a season. The good news: a machine can clean a bathing suit safely, as long as you treat the load like the delicate garment it is. The label decides everything, so read it before the suit ever touches the drum.
Can You Machine Wash a Bathing Suit?
Yes, if the care label allows it — and many do, provided you use a gentle cycle with cold water. Hand-washing remains the gentlest option, so treat the machine as the convenience route, not the default.
Maytag’s swimwear care guidance and Tide Cleaners both point to the same short list of conditions: a delicate cycle, cold water, and a mesh bag to keep the fabric from snagging. The Wirecutter’s swimsuit guide goes further and treats hand-washing as the baseline, which tells you how much the fabric prefers a light touch.
Two caveats matter here. Some swimwear is constructed in ways that should never see a drum at all — one manufacturer explicitly says certain swimwear is hand-wash only, and another says never machine-wash swimwear, full stop. If your label says hand-wash, believe it. The other caveat is fabric: suits with lots of structure, padding, or delicate trims are the riskiest candidates.
| Setting | What to Use | Why It Matters |
|---|---|---|
| Cycle | Delicate, gentle, or hand-wash | Standard cycles stretch and snag the fabric |
| Water temperature | Cold | Heat breaks down elasticity and fades color |
| Detergent | Mild, no fabric softener | Softener coats fibers and dulls stretch |
| Protection | Mesh laundry bag | Stops straps catching on other items |
| Load partners | Similar lightweight items only | Towels and denim abrade the suit |
| Spin | Low | High spin twists and warps the fit |
| Drying | Air-dry, shaded | Dryer heat is the fastest way to ruin a suit |
Machine-Washing Steps That Protect the Fabric
The routine takes about two minutes of prep and works for any suit the label says can go in the machine.
- Read the care label first. If it says hand-wash only, stop there and wash it in the sink instead.
- Rinse off chlorine, salt, and sand in cool running water before the suit goes anywhere near the washer.
- Turn the suit inside out and fasten any hooks, ties, or closures so they don’t catch on fabric.
- Place it in a mesh laundry bag. A zippered bag keeps straps from wrapping around the agitator or other clothes.
- Choose the delicate or gentle cycle with cold water and a mild detergent. Skip fabric softener entirely.
- Wash with similar lightweight items only — never a full load of towels.
- Pull the suit out promptly when the cycle ends. Leaving it damp in the drum invites odor and mildew.
- Air-dry flat or on a rack in the shade. Don’t wring it out, and keep it out of direct sun.
If you’re not sure which detergent to buy, our roundup of the best mild detergents for bathing suits covers the gentlest options for stretch fabrics.
The detergents and cycles that treat swimwear gently follow the same logic as Tide Cleaners’ swimwear dos and don’ts: mild soap, no softener, no heat. You can read their full swimwear care guidance for the reasoning behind each one.
What Actually Ruins a Bathing Suit in the Wash?
Heat, agitation, and residue are the three culprits, and each one attacks the fabric differently.
Heat is the worst offender. Warm or hot water — and especially a dryer — degrades the elastane that gives a suit its stretch, which is why cold is the consistent recommendation across every source. Agitation comes second: a normal cycle tumbles the suit against zippers, buttons, and heavy cotton, and that friction causes pilling, snags, and permanent stretching. Residue is the sneaky one. Chlorine and salt left on the fabric keep working on the fibers after you take the suit off, and fabric softener leaves a coating that makes the stretch feel limp.
Color fading shows up too, mostly from hot water and direct sunlight during drying. If a suit already feels loose or looks faded, machine washing will speed that along rather than reverse it — hand-washing is the better call at that point. And wash swimwear after every wear, not at the end of the season, since the longer chlorine and salt sit, the more damage they do.
Frequently Asked Questions
Can I put a bathing suit in the dryer?
No. Dryer heat is the fastest way to destroy the stretch in swimwear, and the tumbling adds unnecessary wear. Lay the suit flat or hang it on a rack in the shade instead. Skip direct sunlight too, since it fades color over time.
What detergent should I use on swimwear?
A mild, gentle detergent is the standard recommendation, and fabric softener should be left out entirely because it coats the fibers and reduces stretch. A small amount goes a long way — you don’t need a full cap for one or two suits.
How often should I wash a bathing suit?
After every wear, and promptly. Chlorine, salt, sand, and sunscreen all keep breaking down the fabric while they sit on it, so a quick rinse followed by a wash keeps the suit in shape far longer than waiting until the end of the season.
References & Sources
- Maytag. “How to Wash a Swimsuit” Manufacturer guidance on cycles, water temperature, and mesh bags for swimwear.
- Tide Cleaners. “Dos and Don’ts of Swimwear Care” Detergent, softener, and drying guidance for swimwear fabrics.
- The Wirecutter. “How to Wash Swimsuits” Treats hand-washing as the gentlest baseline for swimwear.