Body shape calculator
Three measurements (four when needed), the FFIT rules as revised in 2020, and two things many calculators do not show: how far one measurement is from changing your result, and where your waist-to-hip ratio falls among 11,119 adults measured in a national health survey.
What the result tells you, and what it does not
You get the FFIT shape name, the differences the rule looked at in inches and centimetres, and the exact rule that fired. You also get a stability note: the smallest change to any one measurement, with the others fixed, that would give a different result. When that is 2 cm or less — this site’s display threshold — a second measurement is worth more than the label.
The result does not rank you, does not use height or weight, and is not a health assessment. A body shape result is a description of how three or four circumferences relate; the outfit pages list options organised by the effect you may want, not corrections.
How to take the four measurements · How the classification works, in full · Men's body type calculator
The revised FFIT-based rules used on this site, checked in this order (inches)
| Shape | Rule | Common-name grouping used on this site |
|---|---|---|
| Hourglass | bust − hips ≤ 1; hips − bust < 3.6; and (bust − waist ≥ 9 or hips − waist ≥ 10) | hourglass |
| Bottom hourglass | hips − bust from 3.6 to under 10; hips − waist ≥ 9; high hip ÷ waist < 1.193 | hourglass (hips lead the bust; also listed with pear) |
| Top hourglass | bust − hips over 1 and under 10; bust − waist ≥ 9 | hourglass |
| Spoon | hips − bust > 2; hips − waist ≥ 7; high hip ÷ waist ≥ 1.193 | pear |
| Triangle | (hips − bust ≥ 3.6 and 0 ≤ hips − waist < 9) or (bust − waist < 0 and hips − waist ≥ 0) | pear |
| Inverted triangle | bust − hips ≥ 3.6; bust − waist < 9; hips − waist ≥ 0 | inverted triangle (some calculators call this apple) |
| Rectangle | |bust − hips| < 3.6; 0 ≤ bust − waist < 9; 0 ≤ hips − waist < 10 | rectangle, banana, straight |
| Diamond | waist larger than both bust and hips | apple |
| Oval | waist > hips and waist ≤ bust | apple |
Rules are checked in the order listed and the first match is returned; some conditions overlap, so order matters. The 2020 revision reintroduced Diamond and Oval into the formula set and added the lower bounds of zero; without them, a waist larger than the hips could be returned as Rectangle, Triangle or Inverted Triangle, or match nothing. Source: Simmons, Istook & Devarajan (2004); Sokolowski & Bettencourt (2020). Details on the methodology page.
The five shape families
- Hourglass — bust at most 1 inch over the hips, hips less than 3.6 over the bust, waist 9 under the bust or 10 under the hips. Includes top and bottom hourglass.
- Pear — hips measuring larger than the bust. This site’s grouping for the FFIT results Triangle and Spoon.
- Rectangle — bust, waist and hips within a narrow range of each other.
- Inverted triangle — bust measuring at least 3.6 inches larger than the hips, waist less than 9 under the bust.
- Apple — this site’s grouping for the FFIT results Oval and Diamond, where the waist measures larger than the hips.
Close to a threshold? Hourglass vs pear, pear vs rectangle and apple vs rectangle go through the conditions.
References
The rules and figures on this page come from the sources below. Reference values are conventions from the literature, not targets.
- Simmons, Istook & Devarajan (2004). Female Figure Identification Technique (FFIT) for Apparel, Part I: Describing Female ShapesJournal of Textile and Apparel, Technology and Management 4(1):1–16 · JTATM 4(1)Defines the nine FFIT shapes (hourglass, top and bottom hourglass, spoon, triangle, inverted triangle, rectangle, diamond, oval) from bust, waist, high-hip and hip circumferences on 3D body scans of North American women. The rules on this site are this set, as later revised.
- Sokolowski (2020). Modification of the Female Figure Identification Technique (FFIT) Formulas to Include Plus Size Bodies3DBODY.TECH 2020 Conference Proceedings · proc.3dbody.tech/2020Shows the 2007 FFIT formulas assumed the waist is smaller than the bust and so failed on many larger bodies; adds the Diamond and Oval rules and a ≥ 0 lower bound to Triangle, Inverted Triangle and Rectangle. This site uses the revised formulas.
- National Center for Health Statistics (2024). National Health and Nutrition Examination Survey: Body Measures (BMX) data, 2017–2018 and August 2021–August 2023CDC / NCHS public-use data files · NHANES BMX_J, BMX_LSource of the waist and hip circumferences behind the waist-to-hip percentiles here: 11,119 adults measured by trained staff. Unweighted, so the percentiles describe the examined sample rather than the US population exactly, and NHANES records no bust measurement.
Questions people ask
Which measurements do I need?
Bust at the fullest point, waist at the narrowest point, and hips at the fullest point, tape level and snug but not tight. Some results also need the high hip — around the upper hip, about 3 in (7–8 cm) below the waist by this site’s convention — because two rules use high hip ÷ waist and, when no earlier rule has matched, the result cannot be resolved without it. In our ANSUR II analysis, 34.7% of records required it; the calculator asks only when it does. Details on the measuring page.
Where do the rules come from?
From the Female Figure Identification Technique (FFIT), developed at North Carolina State University from 3D body scans and published in 2004, as revised in 2020 to correct conditions that misclassified or failed to classify larger bodies. Every threshold is printed on this page and on the methodology page.
Why does my result differ from another calculator?
Results can differ because of formulas (some calculators run the 2007 FFIT set — calculator.net publishes it — while this site runs the 2020 revision), rule order, a missing high-hip measurement, or inputs close to a threshold. A different result elsewhere does not mean either site is broken.
What does the boundary note mean?
The rules use circumference differences in inches and one ratio (high hip ÷ waist). If changing one of your measurements by 2 cm or less, with the others fixed, would give a different result, the note says so and names the measurement. 2 cm is this site’s display threshold. In our ANSUR II analysis, 42.8% of the 1,297 results that did not need a high hip were that close to a different one.
Is one shape better than another?
No. The labels describe relationships among three or four circumferences. They are not diagnoses, health scores or rankings, and the classifier does not use height, weight or BMI.
Is "apple" a shape here?
“Apple” is used differently across styling guides and calculators. This site uses it as a common-name grouping for Oval and Diamond; some other calculators use it for Inverted Triangle. Oval requires the waist to exceed the hips while remaining no larger than the bust; Diamond requires the waist to exceed both. Results always use the FFIT names and say which grouping applies.