It happens every year, that special moment: you excitedly open a swimsuit package, try it on, and something isn't right. Not because your body is flawed. Not because your figure is "complicated." But because swimwear, among all fashion items, is probably the garment that suffers most from the gap between industrial production standards and the diverse reality of women's bodies.
This guide was designed to change that.
At MITCH By AEF, we've chosen to speak to you honestly about cut, fabric, pattern-making, standards, and your body shape, because you deserve real answers, not empty platitudes. What you're about to read here is what an experienced swimwear pattern maker would explain to you in the intimacy of a sewing workshop.
Why is it sometimes so difficult to find a swimsuit that truly fits?
The female body, a reality that standard sizes don't capture
The first thing to understand is that ready-to-wear sizes don't measure a body, they measure an average.
European clothing size standards, codified in standard EN 13402 (adopted and published by the European Committee for Standardization, CEN, and transposed in France by AFNOR), are based on anthropometric surveys conducted on panels of women. These data allow for the definition of "typical sizes," but a typical size is a statistical abstraction, never a real body.
In parallel, standard ISO 8559 (Clothing construction and anthropometric surveys – Body dimensions, International Organization for Standardization, Geneva) provides an international framework for defining body measurements used in clothing manufacturing. This standard specifies measurement points (bust, waist, hip circumference, inseam, etc.) but cannot anticipate the thousands of proportional variations that exist from one woman to another.
In short: two women wearing the same size on the label can have very different bust, waist, and hip measurements simply because their volume distribution is distinct. And that's where the difficulties begin.
Elastane, fabric tension, and material compression – what the label doesn't tell you
A swimsuit is not a t-shirt. Its behavior on the body depends on a precise textile alchemy, often overlooked by buyers.
Elastane (also known by the trade name Lycra®, a registered trademark of Invista) is the elastic fiber that allows a swimsuit to stretch and return to its shape. In swimwear, standard compositions generally range between 15% and 25% elastane, with the rest composed of polyamide (nylon) or polyester. The higher the percentage of elastane, the more stretchable the fabric, but also the more compressive it can be.
However, compression is not uniform depending on the cut and areas of the body. A fabric with 20% elastane will exert different tension whether it covers a flat area (the back) or a curved and voluminous area (the bust or hips). This is why two swimsuits sold in the same size can offer radically different support depending on the body volumes wearing them.
The difference between lining and main fabric also plays a crucial role. A quality swimsuit has an inner lining, usually made of plain fabric, whose composition and textile tension may differ from the outer fabric. This lining must be flexible enough not to create uncomfortable compression, but firm enough to provide real support. A swimsuit without a lining, or with a poor quality lining, will be perceived as "flimsy" or unstructured – even if its size perfectly matches your measurements.
Pattern variations are ultimately the most invisible and most decisive variable. Pattern making is the art of cutting and assembling fabric pieces to create a shape. An experienced swimwear pattern maker knows that:
- the angle of hip cutouts radically changes the perception of volume,
- the inseam height modifies the visual balance between the pelvis and thighs,
- the position of the straps influences the perception of the shoulders,
- chest seams can add volume, reduce it, or simply support.
Two swimsuits of the same size, sold at the same price, can therefore yield completely different visual and comfort results not because of your body, but because of very distinct patterning choices.
The Tower of Babel of international sizes
If you've ever bought a swimsuit online, you've probably noticed that size charts vary considerably from one brand to another. This is no coincidence: there is no universal and binding swimsuit size.
Why European, American, and Asian sizes don't look alike
In Europe, sizing generally follows the recommendations of standards EN 13402 and ISO 8559 — but each country, and often each brand, interprets these recommendations in its own way. A French size 38 does not correspond exactly to an Italian or Spanish size 38.
In the United States, the sizing system (XS, S, M, L, XL) is based on different measurements, with standards defined by ASTM International (American Society for Testing and Materials, standard ASTM D5585 for adult women). American standards have historically evolved towards what industry professionals call "vanity sizing" — a tendency to inflate sizes to flatter consumers. An American size M can thus correspond to a size L or XL in other systems.
Asian sizes — particularly Chinese and Japanese — often rely on different anthropometric standards, based on surveys conducted on populations with smaller statistical proportions. A swimsuit labeled "L" on an Asian platform might actually correspond to a French size S or M.
For swimwear in particular, there is currently no unified, binding international standard. Each brand is free to define its own sizing chart. That's why, at MITCH By AEF, we believe that a detailed size chart, with measurements in centimeters, is the only truly reliable information you should rely on.
Practical advice: Ignore the size label. Measure yourself. Compare your measurements to the chart provided by each brand. This is the only method that truly works.
Female body types:
Understanding your silhouette for better choices
A classification for your comfort, never a judgment
Morphological classifications used in image consulting and textile pattern-making — popularized notably by image professionals such as Trinny Woodall and Susannah Constantine (What Not to Wear, Weidenfeld & Nicolson, 2002), and developed in the professional image consulting practices of the AFPIC (French Association of Image-Consulting Professionals) — are based on a simple principle: observing the relative proportions between shoulders, waist, and hips to identify silhouette families.
These categories are not medical diagnoses. They do not rank bodies. They are visual and educational tools to understand how volumes are distributed — and, in swimwear, how to choose cuts that bring balance, comfort, and confidence.
Every body is unique. These morphological families are trends, indicative benchmarks — not cases you absolutely must fit into.
X-shape body type: Natural balance
General proportions: Shoulders and hips are relatively balanced, and the waist is clearly defined. This is the body type often associated with what the industry calls a "hourglass" figure.
Visual characteristics: The difference between waist circumference and hip circumference is pronounced. Shoulders and hips create a natural visual balance. The waist is clearly defined.
Volume distribution: Volumes are distributed relatively symmetrically top and bottom — with a waist that creates a clear break.
Swimsuits often most comfortable: The X-shape body type is often very well served by most cuts, provided the swimsuit respects and enhances the defined waist. Swimsuits with waist cutouts, side ties, or draping effects at the waist are particularly flattering. Two-piece bikinis with high-waisted bottoms naturally accentuate the silhouette.
Cuts that provide the best balance: One-piece swimsuits with cinched waists, classic triangle bikinis, well-supported bandeau tops, coordinated two-piece sets with a well-positioned waist.
Common mistakes: Choosing a one-piece swimsuit that is too straight or too architectural and hides the waist. Opting for a swimsuit with a fabric that is too rigid and does not adapt to curves.
8-shape body type: Amplified curve
General proportions: Close to the X-shape body type, but with more pronounced volumes at both the top and bottom. Bust and hips are generous, waist is very defined.
Visual characteristics: Very curvy silhouette, with a succession of generous roundness. The waist may appear even finer in contrast to the volumes of the top and bottom.
Volume distribution: Significant volumes at the bust and hips, well-defined waist. The silhouette is rich in curves.
Swimsuits often most comfortable: This body type needs support — especially at the bust. Swimsuits with light underwire, tops with integrated cups, or structured tops provide the necessary support. For bottoms, a high-waisted bikini or shorts instantly contain and support the hips.
Cuts that provide the best balance: One-piece swimsuits with waist cutouts or waist elastic, bikini tops with reinforced support, high-waisted bottoms, well-structured tankini swimsuits.
Common mistakes: Choosing a triangle bikini top without support for a generous bust — comfort and support will be insufficient. Opting for low-waisted bottoms that can create a feeling of overflow at the hips.
A-shape body type: The strength of the hips
General proportions: Hips are visibly wider than shoulders. The waist is defined or slightly defined. The upper body is narrower.
Visual characteristics: The silhouette widens downwards. Shoulders appear narrower. This is a very feminine body type, often associated with a strong presence of hips and thighs.
Volume distribution: Volumes concentrated at the bottom — hips, buttocks, thighs. The upper body is thinner.
Swimsuits that are often the most comfortable: The goal is to create visual presence at the top to balance generous hips. Ruffled tops, tops with details (embroidery, bold prints, structured cups, wide straps) add this volume. At the bottom, high-waisted cuts with good coverage are generally very comfortable — they embrace the hips without constraining them.
Cuts that provide the best balance: Bikini tops with ornamental details or wide straps, one-piece swimsuits with elaborate necklines (bardot, strapless, wide straps), high-waisted bottoms or comfortable shaping briefs.
Common mistakes: Choosing bottoms with bold patterns and a plain top without details — the eye is then drawn only to the bottom. Opting for very thin strings that can dig in or cut into the hips.
V-shaped body type: The strength of the shoulders
General proportions: Shoulders are wider than hips. The waist may be slightly or moderately defined. Hips are narrow compared to the bust.
Visual characteristics: Slender silhouette, with a strong presence at the top. Structured shoulders give a different posture, often very flattering.
Volume distribution: Volumes concentrated at the top — shoulders, bust. The lower body is slimmer.
Swimsuits that are often the most comfortable: The goal is to balance the top and bottom. Clean and simple tops (thin triangles, bandeau without excessive padding, V-neck or plunging neckline) visually slim the upper body. At the bottom, fabrics with slightly more relief or texture — prints, ruffles, details — add volume where it's welcome.
Cuts that provide the best balance: Bikinis with thin straps or criss-cross straps at the back, bardot tops avoided in favor of falling straps, bottoms with side ruffles or bold prints, one-piece swimsuits with a plunging neckline.
Common mistakes: Choosing tops with voluminous shoulders or very thick straps that further accentuate the width of the shoulders. Opting for overly simple bottoms that create a strong imbalance with the top.
H-shaped body type: The elegant straight line
General proportions: Shoulders, waist, and hips are relatively aligned. The waist is slightly or not at all defined. The silhouette is straight and vertical.
Visual characteristics: Athletic or rectangular silhouette. The body creates a continuous line, without a sharp break at the waist.
Volume distribution: Volumes distributed homogeneously. The bust may be modest. The waist is not the area that visually defines the silhouette.
Swimsuits that are often the most comfortable: The challenge is to create curves where the silhouette naturally has fewer. Swimsuits with cutout effects at the waist (side cutouts, ruched waist effect), ties that cinch at the waist, or sculpting one-piece swimsuits can add this shapeliness. At the top, a little volume or structure (light padding, slightly molded cups) pleasantly shapes the bust.
Cuts that provide the best balance: One-piece swimsuits with waist cutouts or ties, bikinis with lightly padded tops, swimsuits with prints or details centered at the waist, bottoms with a defined waistband.
Common mistakes: Choosing a straight one-piece swimsuit, without any cutouts or structuring effects, which accentuates the verticality of the silhouette. Opting for flat bandeau tops without structure on a modest bust.
O-shaped body type: Embraced roundness
General proportions: Volumes are distributed in a more rounded way throughout the body. The waist may be indistinct. The stomach and bust are the most generous areas.
Visual characteristics: Soft and rounded silhouette, with volumes that envelop the body globally. The waist is not primarily the visual reference area.
Volume distribution: Volumes concentrated mainly at the waist and stomach, but also at the bust. Shoulders and hips can be in similar proportions.
Swimsuits that are often the most comfortable: Comfort is paramount. One-piece swimsuits with slightly compressive fabric (without being restrictive), good stability, and wide straps are often highly appreciated. Cuts that create a flattering effect while remaining flexible provide comfort and confidence. Color-blocking panels (vertical color-blocking) can visually create an elongating central line.
Cuts that provide the best balance: One-piece swimsuits with structuring fabric, V-neckline that elongates the décolletage, vertical color-blocking, vertical stripe patterns, tankini swimsuits that don't restrict the stomach, swimsuit skirts that drape comfortably.
Common mistakes: Choosing swimsuits with horizontal cutouts that interrupt the silhouette. Opting for bandeau tops that compress the bust without support. Avoiding overly thin fabrics that lack hold.
How to measure yourself to find your swimsuit size
There's no mystery: the centimeter measurement method is the only one that truly works , regardless of the website or brand.
Here's how to do it, following the standardized measurement points defined by manufacturing standards (ISO 8559 and EN 13402):
Bust measurement (BM)
Measure horizontally around the fullest part of your bust — this is the most prominent line, usually at nipple level. The tape measure should be horizontal at the back, neither too tight nor too loose. Note the measurement in centimeters.
This measurement is crucial for choosing a swimsuit top or a one-piece swimsuit.
Waist Measurement (WM)
Measure around the narrowest part of your waist, usually between your ribs and belly button. Stand naturally—do not suck in your stomach. The tape measure should skim the skin without compressing it.
This measurement is useful for swimsuits with a fitted waist or a structured waist effect.
Hip Measurement (HM)
Wrap the tape measure around the widest part of your hips and buttocks. This is generally 20 to 22 cm below the waist. Stand straight with your feet together.
This is often the most important measurement for choosing swimsuit bottoms or a one-piece swimsuit.
How to interpret these three measurements to identify your body shape category
You can get an indication of your body shape by comparing these three values:
- If your shoulders and hips are similar , with a significantly smaller waist , you often have an X or 8 shape.
- If your hips are significantly wider than your shoulders , you often have an A shape.
- If your shoulders are significantly wider than your hips , you often have a V shape.
- If all three measurements are relatively close , with no very defined waist, you often have an H shape.
- If your volumes are distributed globally and rounded , with your stomach as the main area, you often have an O shape.
Important: These indications are for educational purposes and are approximate. They do not constitute a diagnosis. Your silhouette is unique, and these categories remain benchmarks—never absolute rules.
What MITCH By AEF really does—and why it changes everything
MITCH By AEF is not a designer brand. It is something rarer, and ultimately more useful: a distribution universe that puts the customer first .
MITCH imports fashion items produced in Asia—swimwear, clothing, accessories—to Europe and makes them accessible to the European market. This is the principle of international dropshipping: sourcing items where they are made, and distributing them here, without the traditional intermediary that inflates prices and dilutes responsibilities.
The real added value of MITCH—protection
When you buy a swimsuit from a foreign platform, you are alone facing a supplier you don't know, in a language you may not speak, with often non-existent recourse.
At MITCH By AEF, it's different. MITCH acts as a protective barrier between you and the Asian supplier. In concrete terms, this means:
- If the product received does not match the description—you are reimbursed. Directly. Without fighting anyone on the other side of the world.
- MITCH handles the dispute with the supplier on its end. You don't have to manage anything.
- This barrier is intentional, structural, and it is the core of the MITCH model. Not a marketing promise—an operational reality.
MITCH By AEF—a universe, not a store
MITCH is not just a place to buy clothes. It is a space where thousands of items from Asia coexist, made accessible at fair prices, in a setting where trust is guaranteed. A universe designed for everyone—all body shapes, all styles, all budgets.
"What everyone is clamoring for"—MITCH's slogan—is not just a phrase. It's a positioning: making available in Europe what is already being worn everywhere else in the world, without scams, without opacity.
→ View our ÉDITION SOLEIL 2026 swimwear
FAQ—Frequently Asked Questions about Swimwear Sizes and Body Types
How to choose between one size and another if I am between two sizes?
The general rule for swimwear: if you hesitate for the bottom, go up a size. If you hesitate for the bikini top, it depends on your chest. A generous bust will need support—opt for the larger size or choose a model with reinforced support. A modest bust may prefer the smaller size for a snug and non-floating fit.
My swimsuit from last year doesn't fit me anymore, even though my size hasn't changed. Why?
Elastane degrades over time with chlorine and sun exposure. A swimsuit will gradually lose its elasticity and supportive power—sometimes as early as the first season if not cared for properly. It's not your body that has changed, it's the fabric that has lost its technical properties.
Why doesn't the same swimsuit fit me the same way it does in the picture?
Several factors come into play: the model often has a "standard" body shape for which the swimsuit was designed and patterned. If your proportions are different, the result will be different. This is why detailed cut descriptions and measurement charts are more useful than photos alone.
Can I wear a one-piece swimsuit if I have a large bust?
Absolutely. A well-designed one-piece swimsuit for larger busts generously incorporates reinforced lining, wide non-stretch straps, and sometimes light underwire. The support of a good one-piece swimsuit can be superior to that of a classic triangle bikini.
How do I care for my swimsuit to keep its shape?
Rinse it in cold water immediately after each use, without wringing it. Hand wash with a mild soap. Never machine wash or tumble dry—heat destroys elastane. Do not let it dry in direct sunlight, lay it flat in the shade. A well-maintained swimsuit retains its properties much longer.
Does the size indicated on my swimsuit correspond to my jeans size?
No, and this is one of the most common mistakes. Swimwear has its own specific sizing logic, often different from ready-to-wear clothing. Rely only on centimeter measurements—not the size label.
Are swimsuit sizes standardized in France?
In France, textile size standards are regulated by AFNOR (French Association for Standardization), in conjunction with European EN 13402 and international ISO 8559 standards. However, for swimwear, no mandatory standard applies to brands, which remain free to define their own charts. Hence the importance of always referring to measurements in centimeters rather than the letter or number of the size.
Our promise at MITCH By AEF
We didn't create MITCH By AEF to sell swimsuits. We created it so that buying a swimsuit online from Europe would no longer be a gamble.
The Asian fashion market is immense, varied, accessible—but navigating alone between suppliers, deadlines, uncertain sizes, and unmanageable disputes is exhausting. MITCH exists to remove this friction. You choose, you order. If it doesn't fit, you get a refund—and we handle the rest.
It's as simple as that. And that's what sets us apart.
- In the article: "Asian fashion accessible in Europe, without the risks. Explore the SUN EDITION 2026 →"
- After the body shape section: "Do you recognize yourself? Find your cut in the MITCH By AEF universe →"
- After the customer protection section: "Order without stress. If it doesn't suit you, you get a refund—we'll take care of the rest →"
- At the end of the article: "What everyone is clamoring for—this summer, uncompromising and risk-free. →"
Published by MITCH By AEF · Body Shape & Swimwear Guide