Key takeaways
- Identifies one of five body shapes (hourglass, pear, apple, rectangle, inverted triangle) from bust, waist, and hip measurements using the FFIT classification.
- Calculates waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) — both better cardiometabolic risk indicators than BMI alone.
- Health context, not aesthetic judgment. We surface what each ratio suggests about visceral fat and risk, not how you "should" look.
- Calculations run in your browser. No tracking, no account, no data transmission.
- Pair with our BMI Calculator for a fuller body-composition picture.
How it works
We compute three things from your measurements: a body shape category based on the FFIT classification, your waist-to-hip ratio (WHR), and your waist-to-height ratio (WHtR).
The body shape category is descriptive — it tells you how your bust, waist, and hip measurements relate to each other. Hourglass, pear, apple, rectangle, and inverted triangle are the five FFIT shapes, defined by ratios within ±5% windows. The category is most useful for apparel sizing and is included for context, not health interpretation.
WHR and WHtR are the clinically meaningful numbers. WHR captures whether fat is stored peripherally (hip and thigh, "pear") or centrally (abdomen, "apple"). WHtR more directly measures abdominal adiposity. Both are more strongly associated with cardiovascular and metabolic risk than BMI alone.
The science behind it
Why fat distribution matters
Visceral adipose tissue — the fat stored around organs in the abdominal cavity — is metabolically active in ways that subcutaneous fat is not. It releases inflammatory cytokines, free fatty acids, and adipokines that drive insulin resistance, atherogenic dyslipidemia, and endothelial dysfunction. Two people with the same BMI can have dramatically different visceral fat profiles, and dramatically different cardiometabolic risk (Neeland et al., Lancet Diabetes Endocrinol 2019).
Waist-to-hip ratio thresholds
The WHO defines elevated cardiometabolic risk as:
- Women: WHR ≥ 0.85
- Men: WHR ≥ 0.90
These are population-level thresholds derived from cardiovascular outcome data. Individual risk depends on additional factors including blood pressure, glucose control, lipid panel, family history, and lifestyle.
Waist-to-height ratio: the simplest rule
Ashwell et al.'s 2012 meta-analysis found waist-to-height ratio is a stronger predictor of cardiovascular disease, diabetes, and all-cause mortality than either BMI or WHR alone. The rule of thumb is simple: keep your waist less than half your height.
- WHtR < 0.4: low risk (potentially underweight)
- WHtR 0.4–0.5: healthy
- WHtR 0.5–0.6: increased risk
- WHtR > 0.6: high risk
Unlike BMI, WHtR works comparably well across sexes, ages, and ethnicities — making it a reasonable universal metric.
FFIT body shape categories
The Female Figure Identification Technique (Simmons et al., 2004) sorts women's bodies into five categories based on ratios of bust, waist, and hip:
- Hourglass: bust and hips within 5%, waist at least 25% smaller
- Pear (triangle): hips noticeably larger than bust
- Apple (oval): bust larger than hips, less waist definition
- Rectangle: bust, waist, hips within 5% of each other
- Inverted triangle: bust noticeably larger than hips
FFIT was developed for apparel sizing and anthropometric research. It is descriptive, not diagnostic. The category itself does not determine health; the underlying fat distribution (captured by WHR and WHtR) is what matters clinically.
Life-stage shifts
Body shape changes across life stages. Pregnancy temporarily redistributes weight; puberty shifts hip and bust ratios; menopause shifts fat from peripheral to central storage as estrogen falls. PCOS users frequently see android (apple-pattern) fat accumulation driven by elevated androgens and insulin resistance. None of these patterns are character flaws — they are physiology, and the relevant question is whether your cardiometabolic markers (BP, glucose, lipids, sleep, energy) are in healthy ranges.
References
- Waist-to-height ratio is a better screening tool than waist circumference and BMI — Ashwell et al., Obesity Reviews 2012
- WHO waist circumference and waist-hip ratio report — WHO Expert Consultation 2008
- FFIT female figure identification technique for apparel — Simmons et al., Clothing and Textiles Research Journal 2004
- Visceral adipose tissue and cardiometabolic risk — Neeland et al., Lancet Diabetes Endocrinol 2019
How to use this calculator
- Measure your bust. Wrap a flexible tape around the fullest part of your bust, level all the way around. Wear a non-padded bra or no bra; do not pull tight.
- Measure your natural waist. The narrowest point of your torso, usually about 2.5 cm above your belly button. Exhale gently before reading the number.
- Measure your hips. Wrap the tape around the widest point of your hips and rear. Stand with feet together and weight evenly distributed.
- Enter your height. For waist-to-height ratio, which is a stronger cardiometabolic indicator than waist-to-hip alone.
- Read your shape and ratios. You will see your FFIT body shape category, your WHR, and your WHtR — with health context for each.
Limitations & medical disclaimer
- Body shape is descriptive. It is not a health diagnosis.
- Body composition (DEXA, BIA, skinfold) gives a more accurate read on body fat percentage than any tape-measure ratio.
- During pregnancy, abdominal measurements are not meaningful for body composition tracking.
- WHR and WHtR are screening numbers. Cardiometabolic risk depends on many factors (BP, glucose, lipids, family history) that no calculator measures.
- Tape measurement is sensitive to technique. For trend tracking, measure at the same time of day, same point on the body, with consistent breath.
- HerCalc is for educational use only. For health concerns related to weight or body composition, consult a qualified healthcare provider.
HerCalc tools are educational and do not replace professional medical advice. Always consult a qualified clinician for diagnosis or treatment decisions.
Frequently asked questions
How is body shape categorized? +
We use the FFIT (Female Figure Identification Technique) classification, the standard in apparel and anthropometric research. The five shapes are determined by the ratios of bust, waist, and hip measurements. Hourglass: bust and hips within 5% of each other, with waist at least 25% smaller. Pear: hips noticeably larger than bust. Apple: bust larger than hips, with less waist definition. Rectangle: bust, waist, and hips within 5% of each other (no narrow waist). Inverted triangle: bust noticeably larger than hips. The category is descriptive — it carries no value judgment.
What is waist-to-hip ratio (WHR), and what is a healthy value? +
WHR is your waist measurement divided by your hip measurement. The WHO defines a healthy WHR for women as 0.85 or below; ratios above 0.85 are associated with elevated cardiometabolic risk regardless of BMI. WHR captures fat distribution: a high ratio reflects more abdominal (visceral) fat, which is metabolically more harmful than peripheral (hip and thigh) fat. WHR has stronger evidence for cardiovascular disease prediction than BMI in many large cohorts.
What is waist-to-height ratio (WHtR), and why is it better than BMI? +
WHtR is your waist measurement divided by your height. A useful rule of thumb: keep your waist circumference less than half your height. A WHtR above 0.5 is associated with elevated cardiometabolic risk; above 0.6 is high risk. Compared to BMI, WHtR works equally well across sexes, ages, and ethnicities, and it directly measures abdominal adiposity rather than total body mass. A 2012 meta-analysis by Ashwell et al. found WHtR is a stronger predictor of cardiovascular disease and diabetes than either BMI or WHR.
Does body shape determine health? +
No, but fat distribution does. The "apple" shape (more abdominal fat) is more strongly associated with cardiovascular disease, type 2 diabetes, and metabolic syndrome than the "pear" shape (more hip and thigh fat) at any given BMI. This is a population-level pattern; individual health depends on far more than measurements. Body shape itself is determined by genetics, hormones, and life stage and is largely outside your control.
How does menopause change body shape? +
Estrogen decline at menopause is associated with a redistribution of body fat from peripheral (hip and thigh) to abdominal storage. Many women shift toward a more "apple" pattern post-menopause, with increased visceral fat even at stable body weight. This shift is one of the reasons cardiovascular risk in women rises sharply after menopause. Strength training and aerobic exercise help maintain favorable body composition.
Does PCOS affect body shape? +
Yes. PCOS is associated with elevated androgen levels and insulin resistance, both of which favor abdominal fat storage. Many users with PCOS notice an increase in waist measurement disproportionate to overall weight gain. Tracking WHR or WHtR over time can be more informative than tracking weight alone for PCOS users. Lifestyle interventions, metformin, and GLP-1 agonists (where indicated) can shift this pattern over time.
I am pregnant. Should I use this calculator? +
No — body shape ratios become meaningless during pregnancy because of normal abdominal expansion. Wait until at least 6 months post-partum (and longer if breastfeeding) before using waist-based measurements as a body composition signal.
Is the FFIT classification scientific? +
FFIT was developed for apparel sizing and anthropometric research, not as a clinical diagnostic. It is descriptive and reasonably reproducible across measurers. The clinically meaningful numbers are WHR and WHtR; the FFIT body-shape category is contextual color, not a health indicator.