Best One-Piece Swimsuits: Ranked by Fit, Torso Length and Fabric

Lands’ End is the top pick among the best one piece swimsuits for most buyers. It is the only brand here with three published lengths, plus sizes to 26W, and a separate DDD-cup swim range. The rule that matters most is to check the length option before the size. A one-piece in the right size and the wrong length will still fail, wet or dry.

How this review was done

This is a desk review, carried out in October 2026. We read each brand’s own size charts, fit guides, and product pages. Nobody wore these suits for this piece, and nothing was wet-tested. Every verdict below is brand-stated fact plus our editorial judgement about what those facts mean for fit.

The table uses two labels. “Not published” means the brand does not publish that detail. “Not checked” means we did not verify it for this review, so you should read the brand’s own page before ordering. We list a price only where we read it on a dated product page.

Why one-pieces are harder to fit than bikinis

A bikini lets you buy the top and bottom in different sizes. A one-piece joins bust, waist, hip, and torso in one garment, so a mismatch anywhere shows up everywhere.

Torso length is the problem a dress size cannot solve, because no dress size measures it. When the torso is too short for you, the suit pulls down from the shoulders, the straps dig, and the leg openings ride up. When it is too long, fabric bunches at the waist and the bust support sits below the bust.

Cup support is the second problem. Most one-pieces are sold by dress size with a shelf bra or light cups, so support is tied to your hip measurement rather than your bust. Fabric is the third problem, because one fabric has to compress, stay opaque, and survive sunscreen and chlorine, with no way to swap a worn-out half.

What to look for

Length. Look for a named length option (Long, Long torso, Long Body) or a size chart that publishes a torso measurement. A height range alone is a weaker signal, because two women of the same height can have very different torsos.

Cup approach. In order of precision: band-and-cup sizing, then a cup range stated per style, then dress size with a shelf bra. Only the first is sized to your bust.

Fabric. Read the composition, whether the suit is fully lined, and the brand’s own care warnings. A brand that warns against chlorine is telling you the suit is not built for regular pool use. Our swimwear fabric guide covers fiber blends and lining in detail.

The best one-piece swimsuits, ranked

1. Best length options: Lands’ End

Lands’ End’s swim chart offers three lengths: Regular, a shorter length, and Long. The Long length is 1 1/4 inches longer and is pitched at women from 5 ft 8 in to 6 ft. The chart also covers plus sizes from 16W to 26W.

• Size range: 16W to 26W in plus. We did not check the full straight-size range.
• Length options: Regular, shorter, and Long.
• Cup approach: Dress sizes, plus a separate DDD-cup swim range.
• Limitation: The Long length is defined by height, not torso. At 1 1/4 inches extra, it may still be short if your torso is long for your height or if you are over 6 ft.

This is the only brand on our list that offers a length option, an extended size range, and a DDD-cup range from one brand. Best for: buyers who know their size but not their length, and plus-size buyers who also need extra torso.

2. Best for a long torso: J.Crew and Andie Swim

Several brands now sell a named long fit. Only Lands’ End, above, says how much longer its Long length is. The rest name the fit without publishing the extra length, so treat them as worth trying rather than as a guaranteed fix.

• J.Crew: some one-pieces come in “Classic” and “Long torso” fits. The added length is not published.
• Andie Swim: offers long-torso options on some styles, across XXS to 3X. The added length is not published.
• Monday Swimwear: sells some one-pieces in a “Long Body” cut, such as the Bahamas One Piece Long Body. That page’s size chart shows the same torso column as Monday’s standard chart (58-59 at P to 70-71 at VVV, in inches), so it does not say how much longer the Long Body cut is. Fabric is 82% nylon and 18% spandex; it was listed at $189 when we checked in October 2026.
• Limitation: none of these three publishes the extra length, so compare your own torso measurement with the brand’s chart and order where returns are easy. Monday, for example, accepts returns within 14 days of delivery on full-price items in original condition.

Our guide to swimwear for long torsos covers the measuring side and the threshold numbers in depth. Best for: a long torso that the Lands’ End Long length does not quite reach, or that wants a wider choice of styles.

3. Best for extended sizes: Summersalt

Summersalt sells swimwear in sizes 0 to 24. Its one-piece chart runs from 2 (XS) to 24 (3X), so straight and plus sizes sit on one continuous chart.

• Size range: 2 (XS) to 24 (3X) in one-pieces.
• Length options: Long-torso fit details are not published.
• Cup approach: Dress and letter sizes, not band and cup.
• Limitation: With no published torso figures, a long-torsoed buyer is ordering blind. If you wear above a 24, Lands’ End’s 16W to 26W range goes further.

Andie Swim, at XXS to 3X, is the nearest alternative and adds long-torso options on some styles. Best for: buyers who sit near the straight-to-plus crossover and want one chart rather than two.

4. Best for a full bust: Fantasie

Fantasie sizes its swim the way a bra is sized: bands 30 to 44 and cups D to J, in UK letters. Your band and cup are chosen independently, so support comes from your bust measurement, not your hip.

• Size range: Bands 30 to 44, cups D to J (UK).
• Length options: Not checked.
• Cup approach: Band and cup.
• Limitation: J cups are sold only in 32 to 40 bands, and the largest cup in a 42 band is GG. The letters are UK letters, and UK and US cup letters diverge above DD, so convert before ordering. The range starts at D, which rules it out for smaller busts.

If you are a US DDD (UK E) and need more length, Lands’ End’s DDD-cup range is the alternative. Monday rates its Bordeaux One Piece Full Coverage and Aruba One Piece A to G, so its one-pieces stop at a G. Best for: D cups and up whose dress-sized suits gape at the side or flatten the bust.

5. Best for lap swimming: Speedo

Speedo says its Endurance+ fabric is “designed to last 20 times longer than conventional swimwear fabrics.” That is Speedo’s claim. We have not tested it, and the quote does not define “conventional.”

• Size range: Not checked.
• Length options: Not checked.
• Cup approach: Not checked. Training suits generally favor a secure fit over shaped cups.
• Limitation: You trade bust support and style range for durability. A full bust may need a band-and-cup suit instead.

The contrast with fashion swim shows up on care pages: fashion brands that use nylon-spandex blends commonly warn against chlorine, so check the care page of any suit you plan to swim laps in. Best for: anyone swimming laps several times a week.

One-piece swimsuits compared

Brand	Size range	Length options	Cup approach	Indicative price band
Lands’ End	16W to 26W (plus); straight range not checked	Regular, shorter, Long (+1 1/4 in)	Dress sizes; separate DDD-cup range	Not checked
Monday Swimwear	PP to VVV (nine sizes; VVV is US 16 to 18)	“Long Body” on some styles; added length not published	Cup range per style, A to D up to A to G	$189 (Bahamas Long Body, Oct 2026)
Summersalt	2 (XS) to 24 (3X)	Long-torso details not published	Dress and letter sizes	Not checked
Fantasie	Bands 30 to 44, cups D to J (UK)	Not checked	Band and cup	Not checked
Speedo	Not checked	Not checked	Not checked	Not checked
J.Crew	Not checked	Classic and Long torso on some styles; added length not published	Not checked	Not checked
Aerie	Not checked	“Available in 2 lengths” on some styles	Not checked	Not checked
Andie Swim	XXS to 3X	Long torso on some styles; added length not published	Not checked	Not checked

Size ranges, length options, and cup approaches come from each brand’s own size charts and product pages, read in October 2026.

What goes wrong, why, and the fix

The straps dig and the legs ride up. The torso is too short, so the suit is stretched between shoulder and crotch. Sizing up loosens the bust and hip without adding enough length. Buy a length option, or compare your torso measurement against a chart that publishes one.

The cups sit low or gape. A shelf bra tied to dress size rarely matches a bust that is larger or smaller than the hip. Choose a style with a stated cup range, or move to band-and-cup sizing.

A pale suit goes sheer. Light colors show through when wet unless the lining is right. Monday publishes this caveat itself: its Clovelly One Piece page says, “Note that ivory is a soft hue that some have found to be sheer when wet.” Check whether the suit is fully lined, or choose a darker color.

The suit fades or bags within a season. Chlorine, sunscreen, and heat break down spandex. Rinse in cold fresh water after every wear. If you swim in pools often, buy a suit built for chlorine.

Who this list is not for

This list does not cover competition race suits. If your torso is short, Lands’ End’s shorter length and Aerie’s two-length styles are the starting points. Monday sells a Maternity Aruba One Piece, but this list did not assess maternity fit. If you wear above a 26W, or need a band above 44, none of these picks are confirmed to fit you. Anyone who needs a wet-tested verdict should note that this is a desk review.

FAQ

How do I know if I need a long torso one piece?

You likely need one if regular one-pieces fit your bust and hip but pull down at the shoulders or ride up at the leg. Measure your torso, then choose a brand with a named long fit; Lands’ End is the only one here that publishes how much longer its Long length is.

Should I size up in a one-piece if I have a long torso?

Usually you should not. Sizing up loosens the bust and hip while adding only a little length. A dedicated length option fixes the actual problem.

Is a one-piece or a bikini better for a big bust?

A bikini is easier, because the top and bottom can be different sizes. A one-piece works well when it is band-and-cup sized, as Fantasie’s is.

Which one-piece fabric lasts longest in chlorine?

A suit sold for training will usually outlast a fashion suit. Speedo says its Endurance+ fabric is “designed to last 20 times longer than conventional swimwear fabrics,” a claim that varies by region. Fashion brands in nylon-spandex blends often warn against chlorine on their own care pages.

Before you order

Every pick above depends on two numbers you can take at home: your torso length and your bust. Get those right first, then choose the brand whose chart actually publishes them. Our swimwear measuring guide walks through both.