Find your perfect bikini size from body measurements. Get top and bottom sizes, cup sizing, body shape analysis, and style recommendations for your figure.
Finding the right bikini size is notoriously difficult. Unlike most clothing where a single size covers everything, swimwear sizing depends on separate measurements for the top and bottom, the specific coverage style, and your unique body proportions. Many women need different sizes for tops and bottoms — something sets don't always accommodate. The same style can also fit differently once fabric stretch and support level are part of the equation.
This bikini size calculator uses your bust, underbust, waist, and hip measurements to determine both your top and bottom sizes independently. It also calculates your cup size, identifies your body shape, and recommends bikini styles that flatter your figure most effectively.
Whether you're shopping online (where trying things on isn't possible) or overwhelmed by the variety of styles available, this calculator eliminates guesswork. The style guide explains coverage levels from full to string, and the body shape analysis helps you choose tops and bottoms that create your desired silhouette.
Buying bikinis online has a high return rate because top and bottom sizing rarely match cleanly across brands. This calculator helps you size those pieces separately so you can order a set that actually fits your body instead of forcing one label to do both jobs.
It is useful because coverage style and body proportions matter as much as the raw measurements. Seeing top size, bottom size, and body-shape guidance together makes the choice more practical.
Cup size = bust - underbust (each inch = one cup). Top size based on bust: <32" XS, 32-34" S, 34-36" M, 36-39" L, 39-42" XL. Bottom size based on hips with same ranges. Body shape from bust:hip:waist ratios.
Result: Top: M (30D), Bottom: L, Body Shape: Pear
With a 34" bust and 30" underbust, the cup difference is 4" (D cup) on a 30 band. The 37" hips indicate a size L bottom, while the 34" bust is a size M top — meaning separate pieces should be ordered rather than a matching set.
Unlike standardized clothing sizes, bikini sizing varies dramatically between brands. A medium in one brand might equal a small or large in another. This is why measurement-based sizing is far more reliable than simply ordering your usual letter size. Always consult each brand's specific size chart and compare your measurements to their ranges rather than assuming your universal size.
The four primary body shapes — hourglass, pear, inverted triangle, and rectangle — each have bikini styles that enhance natural proportions. Hourglass shapes are fortunate to look great in almost any style. Pear shapes (larger hips than bust) benefit from drawing visual attention upward with embellished or brighter-colored tops. Inverted triangles (broader shoulders) look balanced with simple tops and detailed bottoms.
When shopping online, check the return policy before ordering — many swimwear vendors have strict guidelines. Order two sizes of the same style to compare. Read reviews from buyers with similar measurements. Avoid trying on swimwear without underwear for hygienic return purposes. Once you find a brand whose sizing works for you, stick with it to minimize future sizing surprises.
If your top and bottom sizes differ (very common), buy separates. About 40-60% of women need different sizes for top and bottom. Many brands now sell pieces individually specifically for this reason.
Measure bust at the fullest point (usually across the nipple line) while wearing a well-fitting unpadded bra. Measure underbust snugly directly below the bust. The difference determines your cup size.
It depends on your body shape. Hourglass figures look great in most styles. Pear shapes benefit from attention-drawing tops (bandeau, embellished) with moderate-coverage bottoms. Athletic builds can add curves with ruffled tops and tie-side bottoms.
For bottoms, err toward true to size — too small creates unflattering lines, too large slides. For tops, sports and halter styles can size down for more support; triangle styles should be true to size or slightly larger.
Full coverage is most versatile and comfortable for active swimming. Moderate/classic is the most popular balance. Cheeky and Brazilian work best on toned figures. Choose based on your comfort level and intended activity.
The band should be snug (two fingers underneath), cups should fully contain breast tissue without spillover or gaping, and straps should support without digging. The center gore (between cups) should sit flat against your sternum.