Calculate Body Mass Index with category
Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify · Updated July 2026 · Formulas verified against official Indian government sources
The BMI Calculator measures Body Mass Index — your weight relative to your height — and classifies it into underweight, normal, overweight, or obese categories. Enter your height and weight in metric or imperial units and it returns your BMI and category instantly. Importantly, this calculator also references the Asian-Indian BMI cut-offs recommended by the ICMR, which are lower than the standard WHO thresholds because people of South Asian origin tend to carry more body fat and face cardiovascular and diabetes risk at a lower BMI. BMI is a useful screening indicator but not a complete measure of health, since it does not distinguish muscle from fat.
BMI is calculated as weight in kilograms divided by height in metres squared: BMI = kg ÷ m². The WHO classifies BMI under 18.5 as underweight, 18.5–24.9 as normal, 25–29.9 as overweight, and 30 and above as obese. For Asian-Indian populations the ICMR recommends stricter thresholds — overweight from 23 and obese from 25 — because South Asians develop metabolic risk (type 2 diabetes, heart disease) at lower BMI levels. BMI does not account for muscle mass, bone density, or fat distribution, so athletes may read as "overweight" despite low body fat. Use it as a screening tool alongside waist circumference and medical advice.
| Category | WHO (global) | ICMR (Indians) |
|---|---|---|
| Underweight | Below 18.5 | Below 18.0 |
| Normal | 18.5 – 24.9 | 18.0 – 22.9 |
| Overweight | 25.0 – 29.9 | 23.0 – 24.9 |
| Obese | 30.0 and above | 25.0 and above |
South Asians develop type-2 diabetes and heart disease at a lower BMI than other populations, so the ICMR (2009) guidelines flag risk earlier than the global WHO thresholds. By Indian standards, "overweight" begins at a BMI of 23, not 25.
Two people can share the same BMI but carry very different amounts of body fat. Research on South Asian bodies shows we tend to have more visceral fat (fat around the organs) and less muscle at any given BMI, which raises the risk of diabetes, high blood pressure, and heart disease at weights that would be "normal" for a European. That is why the ICMR and the Indian government lowered the thresholds: the same number means more risk for an Indian body.
Take someone 170 cm tall weighing 70 kg. BMI = 70 ÷ (1.70 × 1.70) = 24.2. By the WHO scale that is comfortably "normal". By the ICMR scale it is "overweight", because the Indian cut-off is 23. Same body, same number — but the Indian guideline says it is already worth acting on. This is exactly the gap most global BMI calculators hide, and why using Indian cut-offs matters here.
BMI is a screening number, not a diagnosis. It cannot distinguish muscle from fat, so a fit, muscular person may register as "overweight" while someone with low muscle and high belly fat may register as "normal". Pair BMI with waist circumference — above 90 cm for men or 80 cm for women signals abdominal-fat risk for Indians regardless of BMI — and always confirm with a doctor before making health decisions.
To reverse BMI into a weight range, multiply the BMI limits by your height in metres squared. At 170 cm (2.89 m²), the WHO "normal" band is about 53–72 kg, while the stricter ICMR band is about 52–66 kg. So an Indian aiming for the lower-risk range at this height should target roughly 52–66 kg rather than treating 72 kg as fine. Enter your own height in the calculator to see your personal range.
For Indians and South Asians, the ICMR recommends a healthy BMI range of 18.5–22.9. A BMI of 23–27.4 is considered overweight and 27.5 or above is obese — lower than the Western WHO cutoffs of 25 (overweight) and 30 (obese), because Indians carry higher body fat at lower BMIs.
BMI is calculated by dividing your weight in kilograms by the square of your height in metres: BMI = kg ÷ m². For example, a person weighing 70 kg at 1.75 m height has a BMI of 70 ÷ (1.75 × 1.75) = 22.9, which falls in the healthy range.