BMI calculator (with Indian cut-offs)

Your BMI (body mass index) is your weight in kilograms divided by your height in metres squared. For most adults the WHO calls 18.5 to 24.9 normal, but Indian guidelines use lower cut-offs: 23 and above counts as overweight and 25 and above as obese, because South Asians tend to carry more body fat and develop diabetes at a lower BMI.

How is BMI calculated?

BMI = weight (kg) ÷ height (m)²

Say you're 168 cm tall and weigh 70 kg. 1.68 × 1.68 = 2.82, and 70 ÷ 2.82 = 24.8. On the WHO scale that's still "normal". On the Asian-Indian scale it's "overweight".

That gap is the whole reason this calculator shows both.

Why do Indians have different BMI cut-offs?

At the same BMI, people of South Asian origin on average have a higher body fat percentage and more fat around the abdomen than people of European origin. In 2004 a WHO expert consultation published in The Lancet concluded that the share of Asian people at high risk of type 2 diabetes and heart disease is substantial below the usual overweight cut-off of 25, and suggested extra public-health action points for Asian populations.

India went further. The 2009 consensus guidelines for Asian Indians (published in JAPI by a group of Indian experts) set these ranges:

If you live in India or are of South Asian origin, the Asian-Indian column is the more useful one for health risk.

What BMI can't tell you

BMI only knows two numbers, height and weight. So:

• Muscle reads as "fat". A regular lifter at 80 kg and 175 cm (BMI 26.1) may have a slim waist and low body fat. BMI still says obese on the Indian scale.
• It says nothing about where fat sits. Belly fat matters more for heart and diabetes risk. The same Indian guidelines suggest a waist circumference above 90 cm for men and 80 cm for women as a warning sign.
• It isn't for children or pregnancy. Kids and teens use age- and sex-specific BMI charts, not these adult ranges.

That's why trainers usually pair BMI with a waist measurement or a body fat estimate. You can get one from the body fat calculator using a tape measure.

What should you do with your number?

• Normal on both scales: keep doing what you're doing. Track your waist every few months.
• Normal on WHO, overweight on the Indian scale: this is the range many people ignore. A modest calorie deficit and regular training usually move it. The calorie calculator gives you a daily target.
• Obese on either scale: worth a check-up for blood sugar, blood pressure and cholesterol, and a plan with a doctor or dietitian.
• Underweight: aim for a small calorie surplus with enough protein. The protein calculator tells you how much.

Losing even 5 to 10% of body weight improves blood sugar and blood pressure for many people, so you don't need to hit the "ideal" number to get real benefits.

For trainers and gym owners

A BMI reading at the first session gives a baseline, but it's a poor progress metric for members who are lifting, since they can gain muscle and lose fat with little change on the scale. Waist size, photos, strength numbers and attendance tell a better story. If you run a gym, our guide on onboarding new members in the first 30 days covers which numbers to record and when.

This calculator is for general information and isn't medical advice.