XL isn’t a fixed measurement — pick swimwear size from the brand’s own chart using your bust, waist, hips, and torso, since one brand’s XL 18 can differ from another’s.
A swimsuit that pulls at the shoulders or digs in at the waist usually isn’t the wrong size — it’s the wrong chart. The letter on the tag means nothing on its own. What decides the fit is a tape measure and the specific brand’s numbers, and the measuring itself takes about five minutes.
What Does XL Actually Mean In Swimwear?
XL is a label each brand defines for itself, so the same letters can cover different bodies from one label to the next. Lands’ End, for example, maps women’s XL to numeric size 18 in its swimsuit chart — approximately a 44-inch bust, a 37 to 38½-inch waist, and 46½-inch hips. Its women’s tops chart also calls size 18 XL, but lists size 20 as XL too, with a 46-inch bust. Same brand, different product line, different numbers. That’s the whole reason generic sizing assumptions fail.
How Do You Measure For A Bathing Suit?
Measure over close-fitting underwear or a bra, keep the tape level and parallel to the floor, and let a friend help where you can — a self-measured bust and hip reading is where most errors start. Lands’ End’s official swim chart lays out five measurements, and you want all of them before you shop.
- Bust: arms relaxed at your sides, tape around the fullest part of the bust.
- Waist: around the narrowest point; add ½ inch for comfort.
- Hips: heels together, tape around the fullest part of the hips.
- Torso: from the shoulder, diagonally over the fullest part of the bust, down between the legs, and back to the start. This one matters most for one-piece suits.
- Height: stocking feet, back against a wall, floor to the top of your head. This tells you whether you need petite, regular, or tall proportions.
Getting the torso reading right is the step most people skip, and it’s the measurement that decides whether a one-piece pulls at the shoulders or bags at the rear.
Which Size Should You Pick When Your Measurements Disagree?
Fit the largest relevant measurement first, then let the garment’s stated stretch and fit notes adjust downward — never compress yourself into a smaller size to match a single number. A suit that’s too tight restricts movement and lets straps and seams dig in; one that’s too loose shifts around mid-stroke. If your bust lands in one size and your hips in another, buy for the hips on a one-piece, and split sizes on a two-piece set when the top and bottom are sold separately.
Product pages often carry fit notes the chart doesn’t. Some Lands’ End swim styles state outright that they run large and recommend sizing down for a closer fit, and at least one halter romper lists XL as size 18 with a shoulder-to-hem length of roughly 30 to 31½ inches in regular sizing. Read the specific page before you commit — and check the regular, petite, and long-torso rows, since a suit can match every circumference and still pull if the torso proportion is off. Once you’ve got your numbers, this roundup of tested XL bathing suits shows which styles actually run true to their charts.
| Measurement | How To Take It | Common Mistake |
|---|---|---|
| Bust | Tape around the fullest part, arms down, tape level | Measuring over a padded or bulky bra |
| Waist | Narrowest point, over underwear, add ½ inch for comfort | Pulling the tape tight |
| Hips | Heels together, around the fullest part | Measuring above or below the widest point |
| Torso | Shoulder to shoulder, diagonally down through the legs | Skipping it entirely on a one-piece |
| Height | Stocking feet, back to wall, floor to top of head | Ignoring petite or long-torso sizing |
| Numeric size | Match to the brand’s own swim chart, not a generic XL | Assuming XL means the same everywhere |
| Fit notes | Read the product page for “runs large” or “size down” | Buying the chart size and ignoring the note |
The Sizing Mistakes That Cost You A Return
Nearly every bad swimsuit fit traces back to one of a handful of slips, and all of them are avoidable with the tape still in hand.
- Treating XL as a standard across brands instead of checking each chart.
- Measuring over bulky clothing rather than a bra and underwear.
- Holding the tape tight at the waist instead of snug and level.
- Leaving torso length out of the equation on a one-piece, romper, or swim dress.
- Buying on bust size alone when the waist or hips land in a different range.
- Forcing a two-piece top and bottom into the same size when they’re sold separately.
- Skipping the fit note that says a style runs large.
- Reading a sold-out size as proof the size doesn’t exist. Stock varies by style; Lands’ End lists sizes and availability separately per product.
Lands’ End’s swim size chart is the authoritative reference for its own numbers, and it’s worth opening in a second tab while you measure.
Common Questions
Is XL the same as size 18 in swimwear?
Not universally. Lands’ End lists XL as size 18 on its women’s swimsuit chart, but its women’s tops chart also labels size 20 as XL. The letters only mean something against a specific brand’s own chart, so check the product’s size guide before ordering.
Why does my one-piece pull at the shoulders when the measurements match?
Torso length is the culprit. A suit can match your bust, waist, and hips and still pull if your torso is longer than the garment’s proportion. Look for a long-torso option, which Lands’ End includes alongside regular and petite in its swim chart.
Should I size up or down if a swimsuit runs large?
Follow the product page’s own guidance. Some Lands’ End swim styles state they run large and recommend sizing down for a tighter fit. If no note appears, fit your largest relevant measurement and let the suit’s stretch handle the rest.
Sources
- Lands’ End. “Swim Size Chart” Official swimsuit measurements, including XL 18 and torso sizing by proportion.
- Lands’ End Business. “Women’s Tops Fit & Size Guide” Shows XL 18 and XL 20 with different bust measurements within one brand.