How to Measure for a Swimsuit: The 5-Minute Guide to Your Perfect Size
How do you measure for a swimsuit so it actually fits? Grab a soft tape measure and take five simple measurements: bust, underbust, waist, hips, and torso length. Match those numbers to a brand's swimsuit size chart, and the guesswork disappears. Here is the same step by step routine we use at Be Juliet to help customers order the right size the first time, every time.
How to Measure for a Swimsuit in 5 Simple Steps
Swimwear fits closer to the body than any other piece you own, which is why your usual dress size tells you very little at the water's edge. The good news? Accurate swimsuit measurements take less than five minutes. Wear minimal clothing, use a soft fabric tape measure, and keep the tape snug but never tight, the way a swimsuit should sit on you.
Step 1: Measure Your Bust
Knowing how to measure bust for swimwear is the single most useful skill you can bring to any bikini or one piece. Stand straight with your arms relaxed at your sides and wrap the tape around the fullest part of your chest. Keep the tape level across your back and let it sit naturally, without pulling. This number is the one you compare against the bust range on a swimsuit size chart, and it matters more for tops than bottoms.
Step 2: Measure Your Underbust
Slide the tape down to the spot where a bra band would sit, just below your breasts. This underbust measurement tells you how much support the band of a swim top needs to offer, and it is the same starting point lingerie experts recommend for any fitted garment. Vogue's guide to measuring bra size at home explains exactly why the band is the foundation of a good fit, and the principle transfers directly to swimwear. Read Vogue's bra measuring guide here. If your bust and underbust measurements sit in different size rows on a chart, trust the underbust for banded tops and let the bust guide your cup coverage.
Step 3: Measure Your Waist
Find the narrowest point of your torso, usually right above your belly button, and wrap the tape around it. Keep your stomach relaxed and breathe normally. This measurement matters most for high waisted bikini bottoms and one pieces with defined waistlines, because the waistband should hug you without digging in.
Step 4: Measure Your Hips
Stand with your feet together and measure around the fullest part of your hips and seat. This is the measurement that decides bikini bottom sizing, so take it twice to be sure. If you are between hip sizes, most customers size down for tie side bottoms that adjust, and size up for fixed waistband styles.
Step 5: Measure Your Torso Length
This one is the secret weapon of one piece sizing. Place one end of the tape at the top of your shoulder, in the center, and run it down the front of your body, between your legs, and up your back to the same starting point. Keep the tape close to your skin without tugging. Torso length varies widely between women of the same height, and it is the difference between a one piece that fits like a dream and one that pulls at the shoulders. Our guide to swimsuits for a long torso covers what to look for when this measurement runs long.
How to Read a Swimsuit Size Chart
A swimsuit size chart is only useful when you know which column is yours. Most Be Juliet styles list a size range for the bust, waist, and hips, and your size is the row where all three of your numbers fit comfortably. When your measurements span two rows, choose the row that matches your most important measurement for that style: the bust for tops, the hips for bottoms, and the torso for one pieces.
Here is how that works in practice with our current swim edit:
- Harriet Patchwork Bikini, $58: a mix and match set, which means you can choose a top and a bottom in different sizes. Compare your bust to the top's chart and your hips to the bottom's chart, and you will almost never land on the wrong size.
- Harriet Patchwork Bikini Top, $33: sized by bust and underbust, so take your two measurements from Steps 1 and 2 before ordering.
- Harriet Patchwork Bikini Bottom, $25: sized by waist and hips, with an adjustable high rise that forgives a half inch of difference.
- Shine On Me Black Shimmer Bodysuit, $34: a one piece silhouette, so torso length is the measurement to check first, then bust and hips.
- Ashley Beach Set, $44: a swim ready set with a crop top and skirted bottom, sized by bust, waist, and hips together.
- Flow With Me Cover-Up, $44: not a fitted piece, so you can use your dress size here and save the tape measure for the swimsuit underneath.
Falling Between Sizes? Here Is How to Choose
Most women fall between two rows on a swimsuit size chart, and that is normal. The rule is to prioritize the measurement that the style relies on for support. For a triangle or halter top, your bust wins. For a high waisted bottom, your hips win. For a one piece, your torso wins, because a swimsuit that is too short in the torso cannot be fixed by sizing up without leaving you baggy everywhere else.
When the rest of your measurements sit comfortably in a row, but one number is an outlier, look for styles with adjustability. Tie sides, adjustable straps, and high waisted cuts with elastic all forgive variation, which is exactly why our customers love the mix and match bikinis collection. You can also order a top in one size and a bottom in another without losing the matching look.
The 5 Minute Swimsuit Measuring Routine
Print this checklist or save it on your phone, and measuring becomes a twice a year habit. Bodies change with seasons, workouts, and life, so re measure before every big swim season.
- Use a soft fabric tape measure, never a metal one.
- Measure your bust at the fullest point, with the tape level across your back.
- Measure your underbust where a bra band sits, snug but not tight.
- Measure your waist at the narrowest point, breathing normally.
- Measure your hips at the fullest point, feet together.
- Measure your torso length from shoulder, between the legs, and back to the shoulder.
- Write all five numbers down and compare them to the size chart for the exact style you want.
Two numbers that almost match are still different numbers, so record every decimal and round up only when a chart asks you to. If you are unsure about any step, our size guide answers the questions we hear most often, including how to handle the gap between bra sizes and swim sizes.
Real Fits, Real Reviews
We hear it in reviews all the time: the woman who measured first and finally ordered the right size. Thousands of customers have shared their fits, their favorite styles, and the measurements that worked for them, and you can read every one on our reviews page. Their notes are a practical second opinion that no size chart can replace.
And if a suit still does not feel right when it arrives? Be Juliet offers free shipping on every order and easy returns, so you can try your size with confidence and exchange without friction. We want the measuring tape to be the only math you do at the beach.
Shop Your Size at Be Juliet
You have the numbers, and we have the swimwear. Explore the full Women's Swimwear collection to find your next Harriet set, one piece, or cover up, all sized to fit the real you. If you have questions about a specific style before you order, contact our team and we will help you match your measurements to the right piece.
Frequently Asked Questions
What measurements do I need to measure for a swimsuit?
You need five: bust, underbust, waist, hips, and torso length. Bust and underbust size bikini tops, waist and hips size bottoms, and torso length matters most for one pieces.
How do I measure my bust for a swimsuit?
Stand straight with your arms relaxed, wrap a soft tape measure around the fullest part of your chest, and keep it level across your back. The tape should be snug but not tight.
How should a swimsuit fit?
A swimsuit should hug your body without digging in or gaping. The band should stay in place, straps should not slip, and the fabric should feel secure when you move, stretch, and swim.
Do I need different sizes for a bikini top and bottom?
Often yes. Your bust and hips can sit in different size rows, and mix and match sets like the Harriet bikini let you choose the correct size for each half.
Is torso length important for one piece swimsuits?
Very important. Torso length varies widely between women of the same height, and a one piece that is too short in the torso will pull at the shoulders no matter what the size label says.