Data & method

BMI and its two classifications

BMI = weight (kg) ÷ height (m)²

This site displays every BMI against two published band sets.

• Asian-Indian: underweight below 18.5, normal 18.5–22.9, overweight 23–27.4, obese 27.5 and above.
• WHO international: underweight below 18.5, normal 18.5–24.9, overweight 25–29.9, obese 30 and above.

An important precision that most sites skip: the 2004 WHO expert consultation did not replace the international classification for Asian populations. It retained 25 and 30 as the international classification, and separately identified additional public-health action points at 23.0, 27.5, 32.5 and 37.5 kg/m². Describing 23 and 27.5 as "the Asian BMI categories" is a simplification. Describing them as trigger points at which an Asian population should already be acting is accurate, and that is the framing used here.

A third set exists. The 2009 Indian consensus statement (Misra et al.) proposed, for Indians living in India, overweight at BMI 23 and obesity at BMI 25 — stricter than the 27.5 used on this site. If your BMI falls between 25 and 27.5, a substantial body of Indian clinical opinion would already classify that as obesity. This site uses 27.5 because it comes from the WHO consultation and is the figure used in international comparison, but the disagreement is real and worth knowing about.

Source: WHO Expert Consultation. “Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies.” The Lancet 2004;363(9403):157–163.
Source: World Health Organization. “Obesity: preventing and managing the global epidemic” (WHO Technical Report Series 894, 2000) — the international BMI classification for adults.
Source: Misra A, Chowbey P, Makkar BM, et al. “Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management.” J Assoc Physicians India 2009;57:163–170.

Ideal weight

healthy range = 18.5 × height² … 22.9 × height²

Presented as a range, always, because that is what the method produces. A single "ideal weight" figure requires a precision BMI does not possess. The Devine formula (1974) is shown as a secondary column because people search for it; it was designed for drug dosing, returns one number per height, and is not used as the headline anywhere on this site.

Source: Devine BJ. “Gentamicin therapy.” Drug Intelligence and Clinical Pharmacy 1974;8:650–655 — the origin of the widely quoted “ideal body weight” formula.

Daily calories

Men: RMR = 10×kg + 6.25×cm − 5×age + 5
Women: RMR = 10×kg + 6.25×cm − 5×age − 161

Resting metabolic rate from Mifflin–St Jeor, multiplied by an activity factor of 1.2, 1.375, 1.55, 1.725 or 1.9. Results are rounded to the nearest 10 kcal because the equation carries roughly ±10% uncertainty and a final digit would imply precision that is not there.

Where a page needs a reference height for a sex, it uses 165 cm for men and 152 cm for women — approximate adult averages for India from NFHS-5. Those pages say so on the page.

Source: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr 1990;51(2):241–247.
Reference heights: Approximate adult mean heights for India, National Family Health Survey (NFHS-5), 2019–21. Used only as a reference height for illustrative tables.

Protein

The requirement figures are ICMR–NIN 2020: an estimated average requirement of 0.66 g/kg/day and a recommended dietary allowance of 0.83 g/kg/day for healthy Indian adults, computed from median obligatory nitrogen losses and assuming good-quality protein with an improved cereal : pulse : milk ratio of about 3 : 1 : 2.5.

The 1.0–2.0 g/kg bands shown alongside are sports-nutrition guidance, not a dietary recommendation, and every table on this site labels them that way. They come from the International Society of Sports Nutrition position stand on protein and exercise.

Source: ICMR–National Institute of Nutrition, Hyderabad. “Nutrient Requirements for Indians — Recommended Dietary Allowances and Estimated Average Requirements,” 2020.
Source: Jäger R, Kerksick CM, Campbell BI, et al. “International Society of Sports Nutrition Position Stand: protein and exercise.” J Int Soc Sports Nutr 2017;14:20.

Water

The 30–35 ml per kg per day figure is a standard clinical planning estimate rather than a national recommendation, and this site says so on every water page. European reference values for total water intake (2.0 L/day for women, 2.5 L/day for men under temperate conditions) are given as a cross-check.

Source: EFSA Panel on Dietetic Products, Nutrition and Allergies. “Scientific Opinion on Dietary Reference Values for water.” EFSA Journal 2010;8(3):1459.

Waist and hip

Waist-to-hip risk bands from the WHO expert consultation: increased risk from 0.90 in men and 0.85 in women. Waist circumference action points of 90 cm for men and 80 cm for women from the 2009 Indian consensus statement, against international thresholds of 102 cm and 88 cm. Waist-to-height ratio target of under 0.5.

Source: World Health Organization. “Waist circumference and waist–hip ratio: report of a WHO expert consultation, Geneva, 8–11 December 2008.” WHO, 2011.
Source: Misra A, Chowbey P, Makkar BM, et al. “Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management.” J Assoc Physicians India 2009;57:163–170.
Source: Ashwell M, Gunn P, Gibson S. “Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis.” Obesity Reviews 2012;13(3):275–286.

Rounding

BMI to one decimal. Weights to one decimal in ranges, whole kilograms in tables. Calories to the nearest 10. Protein to whole grams. Nothing here is precise enough to justify more, and showing more would misrepresent the method.

What this site deliberately does not do

• It does not diagnose, and it uses no diagnostic language.
• It does not promise a result from any intervention.
• It does not adjust any published formula with an unpublished factor of its own.
• It does not hide the disagreements between sources — see the BMI note above.

Corrections

If a figure here disagrees with the primary source, the primary source wins and the page gets fixed. Send the URL.