A body shape calculator built on the FFIT method
This body shape calculator sorts four tape measurements — bust, waist, high hip and hips — into the body shapes used by clothing designers: hourglass, bottom hourglass, top hourglass, spoon, triangle (pear), inverted triangle and rectangle. It uses the Female Figure Identification Technique (FFIT), developed at North Carolina State University for apparel sizing, and shows every rule with a tick or a cross so you can see exactly why you got your result.
The result is fashion fit guidance: it helps you choose cuts, sizes and alterations and explains why a pattern fits one area and not another. It says nothing about health or attractiveness, and no shape is better than another. If you want a health-related waist measure, use the waist-to-hip ratio calculator instead.
How to use the Body Shape Calculator
- Choose inches or centimetres.
- Measure your bust at the fullest part, keeping the tape level and snug but not tight.
- Measure your waist at the natural waist, the narrowest part of your torso.
- Measure your high hip about 10 cm (4 in) below the waist, around the top of the hip bones, and your hips at the fullest part of the hips and seat.
- Read your shape, the fit notes and the table of rules; copy the result to share with a tailor.
Body Shape Calculator features
Published rules
The FFIT shape formulas as set out by Lee, Istook, Nam and Park (2007), applied in the published order.
Seven shapes
Hourglass, bottom hourglass, top hourglass, spoon, triangle, inverted triangle and rectangle.
Transparent
Each condition is listed with your numbers marked ✓ or ✗, including near misses.
High hip optional
Without it, the calculator tells you when bottom hourglass and spoon cannot be separated.
Proportion bars
Animated bars show bust, waist, high hip and hips at the same scale.
Body shape formulas (FFIT)
All differences are in inches (the calculator converts centimetres). The rules are checked from top to bottom, and the first one whose conditions all hold names the shape.
| Shape | Rule |
|---|---|
| Hourglass | bust − hips ≤ 1 and hips − bust < 3.6, and bust − waist ≥ 9 or hips − waist ≥ 10 |
| Bottom hourglass | 3.6 ≤ hips − bust < 10, hips − waist ≥ 9, high hip ÷ waist < 1.193 |
| Top hourglass | 1 < bust − hips < 10 and bust − waist ≥ 9 |
| Spoon | hips − bust > 2, hips − waist ≥ 7, high hip ÷ waist ≥ 1.193 |
| Triangle (pear) | hips − bust ≥ 3.6 and hips − waist < 9 |
| Inverted triangle | bust − hips ≥ 3.6 and bust − waist < 9 |
| Rectangle | hips − bust and bust − hips both < 3.6, bust − waist < 9, hips − waist < 10 |
Where the method comes from
FFIT was published by Simmons, Istook and Devarajan in 2004 (Journal of Textile and Apparel, Technology and Management) to help the clothing industry build fit blocks for real body proportions. Lee, Istook, Nam and Park turned it into the formulas above in “Comparison of body shape between USA and Korean women” (International Journal of Clothing Science and Technology, 2007). The full method has nine shapes; diamond and oval need stomach and abdomen measurements and are not part of the 2007 formulas, so they are not offered here. The paper is not freely available; the thresholds were checked against several published reproductions on 24 October 2026.
Getting a reliable result
- Measure over underwear or thin clothing, standing relaxed with feet together, and take each measurement twice.
- Small changes matter near a boundary: a half-inch can move you from rectangle to hourglass. Look at the ✓/✗ table to see how close you are.
- Studies have found that measuring the hip or waist at slightly different heights can put the same person in a different category, so treat the shape as a guide.
- The rules were designed for women’s apparel. For bra, kurti or blouse sizes use the bra size calculator and the kurti measurement chart.
Body Shape Calculator FAQ
How do I calculate my body shape?
Measure your bust, waist, high hip and hips, then compare the differences with the FFIT rules — for example an hourglass has bust and hips within about an inch and a waist at least 9 in smaller than the bust or 10 in smaller than the hips. The body shape calculator applies all seven rules for you.
Can a body shape calculator work from height and weight?
No. Height and weight give BMI, which says nothing about where your width is. Shape depends on the girths at bust, waist and hips, so you need a tape measure.
Is there a 3D body shape calculator?
This tool does not build a 3D model; it uses four measurements and published rules. 3D body scanners measure the same girths automatically.
What is the difference between a pear and a spoon shape?
Both have hips fuller than the bust. A spoon also has a pronounced high hip — the high hip is at least 1.193 times the waist — giving a shelf just below the waist.
Why do I get “Between shapes”?
A few combinations, such as a bust more than 10 in larger than the hips, meet none of the published rules. The calculator then names the rule you come closest to.
Does body shape say anything about health?
No. It is a fit guide for clothes. Health risk linked to fat around the waist is assessed with waist-based measures such as the waist-to-height ratio.