Bikini Calculator - Match Body to Swimsuit

A bikini calculator is a four-measurement tool that classifies your silhouette into one of seven body shapes and points you toward the bikini tops, bottoms, and one-pieces that flatter that shape. You enter the bust, waist, high hip, and hip in inches or centimetres, and the tool returns a named shape, the deltas that drove the decision, and a short list of styles worth trying next time you shop.

• • Choosing a flattering new bikini: Readers shopping for a new swimsuit can enter four measurements and read which cuts, strap widths, and rise levels are likely to suit their shape.
• • Picking styles for someone else: A reader helping a friend or partner shop can borrow four measurements and translate them into a short list of styles to look for.

If you want the same four measurements without the swimwear styling layer, the Body Shape Calculator returns the seven-shape label on its own.

The tool converts every entry to inches, then walks a small decision tree built on three ratios: bust minus hip, high hip minus hip, and waist slimness. The label the tree returns is mapped to a short list of bikini top, bottom, and one-piece styles that work well on that silhouette.

• bust - hip: Signed difference between bust and hip in inches.
• highHip - hip: Difference between upper hip and widest hip. At or below negative one inch flags a shelf-like profile that maps to the spoon shape.
• (bust + hip)/2 - waist: How much smaller the waist is than the average of bust and hip. Values of 9 inches or more count as a defined waist.

When the bust and hip are within 1 inch of each other and the waist is at least 9 inches smaller, the calculator returns Hourglass. Otherwise the silhouette falls into the Rectangle branch. When the bust exceeds the hip by 1 inch or more, the same waist gate splits the result into Top hourglass or Inverted triangle. When the hip exceeds the bust by 1 inch or more, the calculator checks the waist first, then the high hip gap: a defined waist with a high hip 1 inch or more below the hip becomes a Spoon; a defined waist with a small high hip gap becomes a Bottom hourglass; an undefined waist becomes a Triangle.

According to Lee, Istook, Nam, and Park (2007), the seven-silhouette classification used by modern body shape tools is built on bust-hip and waist-hip ratios and is the academic basis for the thresholds applied here.

For readers who already know their band and cup, the Bra Size Calculator pairs a structured bust input with the same bust measurement the calculator uses.

Four short definitions keep the tool honest. None depend on body weight, so the same answer comes out for two people whose weight and height differ but whose ratios match.

Readers who want a single ratio that summarises the same waist and hip inputs can pair this tool with the Waist-to-Hip Ratio Calculator, which uses the same numbers for a fat-distribution number.

Stand in front of a mirror with a soft non-stretchable tape, a notebook, and a few minutes. Take each measurement once, breathe out gently, and write the number down before moving on.

1. 1 Measure the bust: Wrap the tape around the fullest part of the chest, parallel to the floor, while breathing normally.
2. 2 Measure the waist: Find the narrowest part of the torso between the ribs and the hips. The tape should sit flat.
3. 3 Measure the high hip: Place the tape at the upper swell of the pelvis, not at the widest point. The high hip is always smaller than the hip; if your reading is larger, the tape has slipped down.
4. 4 Measure the hip: With feet together, wrap the tape at the widest point below the waist. Remove bulky clothing so the tape sits flat against the body.
5. 5 Pick a unit and read the shape: Choose inches or centimetres in the unit selector. Read the named shape and the deltas, then follow the top, bottom, and one-piece recommendations underneath the result.

A reader measures 36 in bust, 28 in waist, 38 in high hip, and 40 in hips in inches. The tool reads bust minus hip negative 4, high hip minus hip negative 2, waist slimness 10 in. Result: Bottom hourglass.

After taking the measurements, the BMI Calculator adds a height-and-weight reading that sits next to the shape label as a separate conversation, not a substitute for it.

A short list of what the tool does well, and what it is not designed to do, helps you put the result in the right place in your day.

• • A consistent shape label across visits: The same four measurements give the same answer on different days, so the result is comparable over time and across people.
• • Visible deltas, not just a label: Bust-minus-hip and waist slimness appear next to the named shape so the inputs that drove the decision are auditable, and the tool stays useful even when the label sits on the boundary between two shapes.
• • Swimwear-specific recommendations: Every shape label is paired with a short list of bikini styles that flatter that silhouette, so the tool saves a separate trip to a styling guide.
• • Unit-agnostic input: Inches and centimetres are accepted at the input level. The calculator converts internally and reports deltas in inches.

Readers who plan a full wardrobe around a measurement set can pair this tool with the Belt Size Calculator, which uses the same waist and hip inputs for a different accessory.

The tool is honest about which factors change the number, which factors only change the context, and which factors it cannot see at all.

• • The tool is a screening device, not a medical assessment. Persistent concerns about weight, fat distribution, or body composition belong with a clinician, especially if a chronic condition, eating disorder history, or pregnancy is in the picture.
• • The seven labels are an approximation. Real bodies blend categories. The deltas are the more useful signal than the headline word.

According to World Health Organization obesity and overweight fact sheet, a waist circumference of 88 cm or more in adult women signals substantially increased metabolic risk.

Readers who sew their own swimwear from the calculator's measurements can pair this tool with the Fabric Calculator, which converts the same inch and centimetre numbers into yardage and fabric needs.