Methodology
The atlas uses five everyday families for navigation and nine FFIT shapes for precision. This page explains the mapping, the sources, the styling policy and the limits.
womenbodytypes.com is a visual reference to women's body types: what each shape looks like, how it is measured, and how to dress for it, without ranking one shape above another.
Five families, nine shapes
FFIT — the Female Figure Identification Technique — was developed at North Carolina State University from 3D body scans. The original 2004 system described nine shapes. The 2007 formulas expressed seven of them as rules on bust, waist, high hip and hip. The 2020 revision added Oval and Diamond and adjusted the lower bounds for Triangle, Inverted Triangle and Rectangle.
| Everyday family | FFIT shapes | What separates the sub-shapes |
|---|---|---|
| Hourglass | Hourglass · Top Hourglass · Bottom Hourglass | Whether the bust or the hips lead, and the high-hip ratio. |
| Pear | Triangle · Spoon | The high-hip flare: spoon at 1.193 × waist or more. |
| Rectangle | Rectangle | One shape; the waist is a gentler indent. |
| Inverted triangle | Inverted Triangle | Bust lead with a waist drop under 9 inches. |
| Apple | Oval · Diamond | Whether the waist also overtakes the bust. |
The five families are the language of fashion writing and shopping. The nine shapes are what the measurement rules actually return. The atlas uses the families to help you navigate and the nine shapes when the difference changes a seam, a rise or a fit decision.
Where the numbers come from
The distribution figures come from the 2003 SizeUSA sample of 6,318 US women, as summarised by Istook and Newcomb: rectangle 46.1%, spoon 20.9%, inverted triangle 13.8%, hourglass 8.4% and 10.7% other. The summary does not break out the remaining shapes, so the chart leaves them blank rather than inventing a number.
That is one US sample from 2003, not a global average. It is useful for context — rectangle is the largest group in that dataset — not for telling an individual what she “should” be.
Measurement patterns
The plates use shorthand versions of the FFIT rules. The full formulas are in the research papers: Simmons, Istook and Devarajan (2004) for the nine-shape system; Lee, Istook, Nam and Park (2007) for the seven-shape formulas; Sokolowski and Bettencourt (2020) for the revision that added Oval and Diamond. The chart lists the pattern for each family, and the plate pages explain the sub-shape differences in words.
Styling notes: editorial, not clinical
The dressing notes are editorial. They come from pattern-making and fit principles — where a seam sits, how much ease a garment has, how volume balances — not from clinical evidence. They are written as starting points, not rules, and they deliberately avoid “hide”, “slim” and “flatter” framing.
What the categories cannot tell you
- They are not health measures. A shape is not a body-fat measure, a risk score or a diagnosis.
- They are not permanent. Weight change, pregnancy, posture and age can move the measurements across a threshold.
- They are not precise at the boundary. A 2021 study of 1,679 scans found that a 1 cm change in tape placement moved up to 40% of women into a different FFIT category.
- They do not describe a person. Style, comfort, culture and preference are not in the four measurements.
Method questions
Where do the nine shapes come from?
They are the FFIT shapes developed at North Carolina State University: nine categories in the original 2004 system, seven of them written as formulas in 2007, and nine again in the 2020 revision that added Oval and Diamond.
Why does the atlas use five families if FFIT has nine shapes?
Five families are the common language of fashion writing and shopping. Nine shapes are what the measurements actually return. The atlas uses the five families for navigation and the nine shapes when the difference changes a fit decision.
Is the styling advice evidence-based?
The measurement categories are evidence-based; the styling suggestions are editorial. They come from pattern-making and fit principles — where a seam sits, how much ease a garment has, how volume balances — not from clinical evidence. The methodology page explains the separation.
Sources
- Simmons, Istook & Devarajan (2004). Simmons, K., Istook, C. L., & Devarajan, P. (2004). Female Figure Identification Technique (FFIT) for Apparel. Journal of Textile and Apparel, Technology and Management, 4(1). https://www.ergo-eg.com/uploads/books/devarajan_full_106_04%20(3).pdf The original nine-shape FFIT system, developed at North Carolina State University from 3D body scans.
- Lee, Istook, Nam & Park (2007). Lee, J. Y., Istook, C. L., Nam, Y. J., & Park, S. M. (2007). Comparison of body shape between USA and Korean women. International Journal of Clothing Science and Technology, 19(5), 374–391. The seven-shape formula set used by most online calculators. It uses bust, waist, high hip and hip.
- Sokolowski & Bettencourt (2020). Sokolowski, S. L., & Bettencourt, C. (2020). Modification of the Female Figure Identification Technique (FFIT) Formulas to Include Plus Size Bodies. Proceedings of 3DBODY.TECH 2020. DOI 10.15221/20.22. https://doi.org/10.15221/20.22 Adds Oval and Diamond, and non-negative lower bounds for Triangle, Inverted Triangle and Rectangle.
- Parker, Hayes, Brownbridge & Gill (2021). Parker, C. J., Hayes, S. G., Brownbridge, K., & Gill, S. (2021). Assessing the female figure identification technique’s reliability as a body shape classification system. Ergonomics, 64(8), 1035–1051. DOI 10.1080/00140139.2021.1902572. https://doi.org/10.1080/00140139.2021.1902572 1,679 3D scans; moving a measurement by about 1 cm changed the FFIT category for up to 40% of women.
- Istook / SizeUSA distribution (2005). North Carolina State University (2005). Fashion designers ignoring shapes of women’s bodies. Newswise / NC State news release; Newcomb, B., & Istook, C. (2006). Using SizeUSA to improve apparel fit. https://www.newswise.com/articles/fashion-designers-ignoring-shapes-of-womens-bodies 6,318 US women from the 2003 SizeUSA scan survey: 46.1% Rectangle, 20.9% Spoon, 13.8% Inverted Triangle, 8.4% Hourglass, 10.7% other.