Choosing a swimsuit seems simple, but trying it on often leads to confusion: the bust doesn't fit properly, the waistline sags, the bottom is too tight or baggy… Choosing the right size not only affects comfort but also directly impacts confidence in photos and during activities. The correct buying steps are: first, take your measurements; then, consider the style; and finally, combine the fabric elasticity with your personal preference to decide whether to "buy one size larger" or "buy one size smaller."
Measure these key body measurements
Bust: Use a soft measuring tape to measure horizontally around the fullest part of your bust, taking a relaxed breath to get your upper bust measurement.
Underbust/Bottom Circumference: Measure around the narrowest part of your bust, especially important for underwire swimsuits or two-piece swimsuits.
Waist: Measure around your waist (usually the narrowest part between below your ribs and above your navel).
Hips: Stand straight with your feet together and measure around the fullest part of your hips.
Torso Length/Height: The length from the top of one shoulder, through the crotch, to the top of the other shoulder. This is crucial for both two-piece and one-piece swimsuits.
When measuring, wear a close-fitting bra or thin undershirt. The measuring tape should not be too tight or too loose. Record the measurement in centimeters for easy reference to the size chart.
Different Styles Have Different Size Requirements
One-piece swimsuits: Most sensitive to torso length, prone to issues like "tight around the crotch" or "loose around the chest." Measure torso length first, then check elasticity. Mid- to high-waisted designs are more forgiving.
Two-piece bikinis: For the upper body, check the cup size and band size like a bra; for the lower body, check the hip circumference and pant style (high-waisted, low-waisted, thong, etc.). The advantage of two-piece swimsuits is that you can choose sizes for the upper and lower body separately.
Sports/Training swimsuits: Prioritize support and fit, usually running small to prevent slipping. Check for lining, reinforced seams, and shoulder strap width.
Tummy-covering/shaping styles: These are often made of thicker fabric with less elasticity. It's recommended to choose based on your largest circumference and pay attention to stretch.
One-piece swimsuits with skirts or backless styles: Skirts don't affect the size, but for backless styles, consider the back depth and the fastening method to prevent slipping during activity.
Fabric and Elasticity Determine "Buy Larger or Smaller"
High-elastic fabrics (high spandex/Lycra content): Good rebound and fits the skin well; consider buying a slightly tighter fit.
Low-elastic or heavy fabrics: Poor elasticity; it's recommended to choose based on your largest circumference or buy one size larger for comfort during activity.
Lined/Sponge-filled/Underwired: For garments with fixed cups, choose based on your lower bust measurement and cup size, not just your usual size.
Remember: Swimsuits will slightly conform to the body after absorbing water in the water, but they won't "expand" as much as regular clothing.
Understanding Size Charts and International Conversion (Practical Tips)
First, check the brand's specific size chart. The corresponding centimeter measurements for S/M/L vary significantly between brands.Learn to use your bust/underbust/hip measurements to compare to "cup + underbust" or "S/M/L + numerical value". For example: 90cm upper bust and 75cm underbust may correspond to a 75C or M+C cup, depending on the brand.
Common conversions: XS, S, M, and L are better understood as body ranges; numerical sizes (such as 34, 36, 38) are more common in US and UK sizes, so always consult a conversion chart.
Write down your measurements before trying on and compare them directly to the size chart in the store to avoid guesswork.
Key Points to Observe During Trying On and Testing
Fits snugly but not constricting: There should be no obvious overflow or gaping in the bust area; the bust line should be smooth; the shoulder straps should not dig into the shoulders or slip easily.
Fit to the lower body: No obvious marks on the buttocks, but not too loose either; the hem won't roll up.
Torso comfort: Test the range of motion by sitting, bending over, or lifting your legs. For one-piece swimsuits, especially try bending over.
Support and coverage: For athletic swimsuits, ensure adequate support; for tummy-covering swimsuits, check the abdominal coverage.
Second check after swimming: If possible, try it in the water for a while to ensure it doesn't lose its shape or slip after absorbing water.
When trying on swimsuits, move around, sit, and bend over; don't just stand and look in the mirror.
Practical Tips for Purchasing and Care
Two-piece swimsuits are preferable: If your upper and lower body proportions are not standard (long legs, short torso, or vice versa), two-piece swimsuits make it easier to find the right size.
Adjustable shoulder straps/back clasp: Increases fit, especially suitable for those with significant differences in bust and back circumference.
Removable foam/adjustable cups: Convenient for replacement or washing, increasing comfort.
Care: After use, wash the swimsuit with fresh water, lay it flat to dry, and avoid direct sunlight or wringing to prolong its elasticity and shape.
Seasonal/Discount Purchases: After trying on your size, check for discounts from your usual brands, but be cautious of expired fabrics or defective products.
Core principles for choosing a swimsuit: First, take your measurements (bust, underbust, waist, hips, and torso length), then determine the specific size based on style requirements (one-piece swimsuits emphasize torso, two-piece swimsuits can be sized separately for top and bottom, athletic swimsuits tend to be tighter and more fitted) and fabric elasticity. When trying on, focus on checking the fit at the chest, comfort at the hips, shoulder strap support, and freedom of movement; for one-piece swimsuits, be sure to perform a bending and leg-raising test. Remember that different brands have different sizing systems; always refer to a size chart or prioritize adjustable designs. After purchase, proper washing and drying will help maintain the swimsuit's elasticity and shape for longer.
