Body Shape Calculator
Find your body shape from bust, waist, high hip, and hip measurements using the FFIT classification, plus your waist-to-hip ratio
By Waqar Mushtaq · Last updated:
This body shape calculator classifies a woman's figure into one of seven shapes -- hourglass, bottom hourglass, top hourglass, spoon, triangle, inverted triangle, or rectangle -- from four tape measurements: bust, waist, high hip, and hip. It uses the Female Figure Identification Technique (FFIT), a classification developed at North Carolina State University for apparel sizing research, rather than eyeballing a silhouette. Beyond the headline shape, you see every FFIT rule checked against your measurements (so you can tell whether you're a clear-cut match or right on a boundary), and your waist-to-hip ratio compared with the World Health Organization's cut-off -- the part of these measurements that actually says something about health. Enter measurements in inches or centimeters.
How the FFIT Body Shape Rules Work
O(1) calculationb = bust · w = waist · h = hip · differences in inches
hh = high hip -- the ratio separates spoon from bottom hourglass
Waist-to-hip ratio; WHO cut-off for women: 0.85
FFIT compares the differences between your bust, waist, and hip measurements (in inches) and the ratio of high hip to waist. The rules are checked in this order, and the first one that matches is your shape:
- Hourglass -- bust − hip ≤ 1, hip − bust < 3.6, and either bust − waist ≥ 9 or hip − waist ≥ 10
- Bottom hourglass -- hip − bust ≥ 3.6 and < 10, hip − waist ≥ 9, high hip ÷ waist < 1.193
- Top hourglass -- bust − hip > 1 and < 10, bust − waist ≥ 9
- Spoon -- hip − bust > 2, hip − waist ≥ 7, high hip ÷ waist ≥ 1.193
- Triangle -- hip − bust ≥ 3.6, hip − waist < 9
- Inverted triangle -- bust − hip ≥ 3.6, bust − waist < 9
- Rectangle -- hip − bust < 3.6, bust − hip < 3.6, bust − waist < 9, hip − waist < 10
Example: bust 34 in, waist 28 in, high hip 36 in, hip 40 in. Hip − bust = 6 and hip − waist = 12 would make this a bottom hourglass, but high hip ÷ waist = 36 ÷ 28 = 1.286, which is above 1.193 -- so it's a spoon. The same figure with a 32 in high hip (ratio 1.143) is a bottom hourglass.
Centimeter measurements are converted to inches before the differences are compared; the ratio is the same in either unit.
Limits of FFIT: the thresholds are fixed inch differences, so they fit some frame sizes better than others, and a few combinations (for example, hips 10 or more inches larger than the bust with a low high-hip ratio) match no rule at all -- this calculator reports those as unclassified rather than forcing a label. FFIT was designed for women's apparel; it isn't a male body-type system and it isn't a health assessment.
Use Cases
Choosing clothes that fit
Body shape describes how your measurements relate to each other, which is what decides whether a standard size fits at the bust, waist, and hips at the same time. Knowing your shape helps you pick cuts and brands that suit your proportions.
Sewing and pattern alterations
Patterns are drafted for one set of proportions. The bust, waist, and hip differences shown here tell you where a pattern needs grading between sizes.
Tracking changes over time
Measuring every few months shows how your proportions shift with training or weight change -- and the waist-to-hip ratio tracks the change that matters most for health.
Frequently Asked Questions
How do I take my measurements for the body shape calculator?
Use a flexible tape, kept level and snug but not tight, over light clothing:
- Bust -- around the fullest part of the chest.
- Waist -- around the narrowest part of the torso, usually just above the belly button.
- High hip -- about 7 in (18 cm) below the natural waist, around the top of the hip bones.
- Hip -- around the fullest part of the hips and buttocks.
What is the most common body shape?
In the large U.S. and Korean body-scan samples studied with FFIT, rectangle was the most common shape in both countries, while U.S. women were spread across more shape categories overall (Lee, Istook, Nam & Park, 2007).
What's the difference between a spoon and a bottom hourglass?
Both have hips larger than the bust and a defined waist. The difference is the high hip: a spoon has a pronounced "shelf" just below the waist, which FFIT detects as a high hip ÷ waist ratio of 1.193 or more.
Why does the calculator say my shape is unclassified?
FFIT's rules don't cover every possible combination of measurements -- researchers have noted gaps, especially for plus-size figures and for very large bust-to-hip differences. The rule-by-rule table shows which conditions you met, so you can see which shape you're closest to.
Is my body shape a health indicator?
Not by itself. What carries health information is where fat is stored: the WHO uses a waist-to-hip ratio of 0.85 or more in women (0.90 in men) as a marker of substantially increased risk of metabolic complications. That ratio is shown alongside your shape.
Methodology
The formula above is implemented as a standalone module covered by unit tests, so its worked examples are re-checked on every change to the site. It is verified against the authoritative sources listed below.
Not medical advice. This calculator is a general informational tool and cannot account for your individual circumstances. See the terms of use.
Maintained by Waqar Mushtaq. Spotted a result that looks wrong? Report it and it becomes a failing test.