Case 1
- Bust
- 96cm
- Waist
- 76cm
- High hip
- 91cm
- Hip
- 103cm
Hourglass
Open with these valuesBody Shape Calculator
Hourglass
Result: HourglassFFIT sorts four measurements into seven shapes by the gaps between them. A bust-waist drop of 9 in or a hip-waist drop of 10 in makes an hourglass; a high hip more than 1.193 times the waist makes a spoon. It is a clothing-fit label from apparel research, not a health measure.
The numbers at a glance
Held fixed: Bust 96.0 cm, Waist 76.0 cm, High hip 91.0 cm.
| Hip (cm) | Result |
|---|---|
| 80.0 | 6 |
| 100.0 | 7 |
| 103.0Your value | 1 |
| 120.0 | 4 |
| 140.0 | 4 |
Worked examples
Case 2
- Bust
- 90cm
- Waist
- 78cm
- High hip
- 92cm
- Hip
- 104cm
Bottom hourglass
Open with these valuesCase 3
- Bust
- 100cm
- Waist
- 76cm
- High hip
- 88cm
- Hip
- 96cm
Top hourglass
Open with these valuesHow it's calculated
Compare bust − waist, hip − waist, bust − hip, high hip ÷ waist
- StepMeasure bust, waist, high hip and hip with the tape level and snug.
- StepHigh hip is the largest circumference between waist and 75 % of the way up from the crotch.
- StepWork out the gaps: bust minus waist, hip minus waist, bust minus hip.
- ResultRead the first rule below that all four measurements satisfy.
What this number means
The Female Figure Identification Technique came out of apparel research at North Carolina State University, where over 6,000 body scans were cluster-analysed to find shapes that clothing patterns could actually be cut for. It works on gaps rather than sizes: a 9-inch drop from bust to waist means the same thing on a small frame and a large one, which is why every threshold here is a difference and not a ratio, apart from the high hip. The rules overlap on purpose, so they are read as a cascade — the first one your measurements satisfy is the answer, and the original software could also return no match at all. Two things this number is not. It is not a health measure. Shape says nothing about body fat, where fat sits, or risk; waist-to-hip ratio is the measure built for that question, and it uses two of the same four numbers. And it is not robust to sloppy measuring. The 2004 validation paper has a section on measurement location problems, and a 2021 reliability study of 1,679 scans found that moving where waist and high hip are taken reclassified large parts of the sample, with spoon agreeing only 66 percent of the time. High hip is the one most people get wrong: it is the shelf between waist and hip, not the hip itself.
Each shape category was then given ranges of numerical values that corresponded to the body measurements. Numerical values that corresponded to the body measurements that were significant to these new shapes were added into the program code in Visual Basic.
This is not a health measurement
Shape is a clothing-fit category. It carries no information about body fat, fat distribution or metabolic risk, and no shape is healthier than another.
High hip is the measurement to get right
The largest circumference, parallel to the floor, between the waist and 75 % of the way up from the crotch. The 2004 papers never defined it at all — that wording is a later reconstruction of the scanner protocol.
Why oval and diamond are missing
FFIT names nine shapes, but only seven ever got published numbers. Oval and diamond depend on stomach and abdomen measurements the original papers never located, so this page leaves them out rather than inventing thresholds.
The thresholds are inches
FFIT was written in inches, so the calculator converts your centimetres before comparing. The 3.6, 9 and 10 in the rules are 9.1, 22.9 and 25.4 cm.
Commonly misread
My shape tells me something about my health.
It does not. FFIT was built so that clothing could be cut to fit, and the thresholds were fitted to scan clusters, not to any health outcome.
High hip is just another word for hip.
High hip sits between waist and hip, over the upper hip bone. It is the only ratio in the whole rule set, and measuring it at the hip changes the answer.
My measurements sit near a threshold, so the shape is roughly right.
Near a gate it is not roughly right, it is the other shape. A quarter inch of rounding has been shown to move a spoon into the hourglass branch, because hip minus waist crossed 10.
Everyone falls into one of the shapes.
No match is a real outcome. The seven published rules do not cover every combination, and the original software returned no shape for bodies that fell between them.
Reference table
| Shape | FFIT rule (inches) |
|---|---|
| Hourglass | (bust − hip) ≤ 1 and (hip − bust) < 3.6 and ((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 (pear) | (hip − bust) ≥ 3.6, (hip − waist) < 9 |
| Inverted triangle | (bust − hip) ≥ 3.6, (bust − waist) < 9 |
| Rectangle | (hip − bust) < 3.6 and (bust − hip) < 3.6, (bust − waist) < 9, (hip − waist) < 10 |
Questions
How is body shape calculated?
FFIT compares four circumferences — bust, waist, high hip and hip — using the gaps between them. Thresholds of 1, 3.6, 9 and 10 inches, plus a high hip to waist ratio of 1.193, sort the result into one of seven shapes.
Where do I measure the high hip?
At the largest circumference parallel to the floor, between the waist and 75 % of the distance up from the crotch. The 2004 FFIT papers never fixed a location at all; that wording comes from a 2021 reconstruction of the scanner protocol. It is not the hip measurement.
What measurements make an hourglass?
Bust and hip within about an inch of each other, with a drop of at least 9 inches from bust to waist or at least 10 inches from hip to waist. Both conditions have to hold on the same body.
Why does the calculator not have oval or diamond?
The FFIT papers describe nine shapes but only ever published numbers for seven. Oval and diamond rest on stomach and abdomen measurements that were never given a location, so they are left out rather than guessed at.
Does body shape say anything about health?
No. It is an apparel-fit classification derived from scan clusters. Waist-to-hip ratio uses two of the same measurements and is the one with health evidence behind it.
How reliable is the result?
It depends almost entirely on where you put the tape. A 2021 study of 1,679 scans found that changing the waist and high hip definitions reclassified much of the sample, with the spoon shape agreeing only 66 percent of the time.
Sources and last check
Information, not medical advice.