BMI Calculator

What is BMI?

BMI Calculator — Body Mass Index Calculator Free

BMI (Body Mass Index) is a number calculated from your height and weight that estimates whether you are at a healthy weight. It is one of the most widely used screening tools by doctors, dietitians and health professionals worldwide.

The BMI formula is: BMI = Weight (kg) ÷ Height² (m²). For example, if you weigh 70 kg and are 1.70 m tall: BMI = 70 ÷ (1.70 × 1.70) = 24.2. You can do a BMI test online instantly using the free calculator above — no login, no signup. This BMI calculator for Indians uses ICMR Asian cutoffs, making it far more accurate than generic Western tools for South Asians. It also works as a weight calculator — showing your ideal weight range for your height — and supports BMI calculator kg input for metric users.

While BMI is a useful starting point, it does not directly measure body fat. Two people with the same BMI can have very different body compositions. Use BMI alongside waist circumference and other health markers for a complete picture.

How to Use This BMI Calculator

BMI Formula

How to Calculate BMI — Formula, Steps and Examples

The BMI formula is the same worldwide. You need only two numbers — your weight and your height — and a single division. Here is exactly how to calculate BMI manually, in both metric and imperial units.

How to Calculate BMI in kg and cm

This is the method most people in India use. Convert your height from centimetres to metres first by dividing by 100, then square it, then divide your weight by that number.

Worked example — 70 kg, 170 cm:
Step 1: 170 cm ÷ 100 = 1.70 m
Step 2: 1.70 × 1.70 = 2.89
Step 3: 70 ÷ 2.89 = 24.2
By ICMR Asian cutoffs, a BMI of 24.2 falls in the overweight range for Indians, though Western charts would call it healthy.

How to Calculate BMI in Feet and Pounds

Worked example — 154 lb, 5 feet 7 inches:
Step 1: 5 ft 7 in = 67 inches
Step 2: 154 ÷ 67 ÷ 67 = 0.0343
Step 3: 0.0343 × 703 = 24.1

How to Calculate BMI Manually — Step by Step

BMI Calculation Examples — Common Heights and Weights

Note how the same BMI means different things depending on which chart you use. Every figure above is classified using ICMR Asian cutoffs, where overweight starts at 23.0 rather than 25.0.

How to Calculate BMI for Women and Men

The BMI calculation is identical for men and women — there is no separate formula and no gender variable in the equation. A 65 kg woman at 165 cm and a 65 kg man at 165 cm both have a BMI of 23.9.

What differs is interpretation. Women naturally carry a higher body fat percentage than men at the same BMI, so two people with matching scores can have very different body compositions. This is why BMI works best as a screening tool rather than a diagnosis — pair it with waist circumference and body fat percentage for a fuller picture.

Indian & Asian Cutoffs

BMI Calculator for Indians — Why Asian Cutoffs Matter

Standard Western BMI charts were developed for Caucasian populations. Research shows that South Asians develop metabolic diseases at significantly lower BMI values than Caucasians — a finding confirmed by the WHO Expert Consultation on Asian BMI cutoffs, ICMR dietary guidelines and numerous peer-reviewed studies.

At the same BMI, Indians typically carry 3–5% more body fat and have higher rates of abdominal fat compared to Europeans. This increases the risk of Type 2 diabetes, hypertension, and cardiovascular disease at a lower body weight.

This is why DialFit uses ICMR Asian BMI cutoffs — the same standards recommended by the Indian Council of Medical Research and the WHO for South Asian populations. This free Asian BMI calculator applies these lower thresholds automatically so your result is meaningful for Indians, not just the global average.

Asian BMI Categories (ICMR / WHO Guidelines)

Note: Western BMI cutoffs classify overweight as 25+ and obese as 30+. For Indians and other South Asians, these thresholds are set lower because the health risks begin earlier.

Gender Differences

BMI Calculator for Women and BMI Calculator for Men

Ideal Weight

Ideal Weight Calculator — What Should You Weigh?

Your ideal weight is the range that corresponds to a healthy BMI of 18.5–22.9 for your height. This is calculated using the same formula as BMI, working backwards from the healthy range.

For example, for someone who is 165 cm tall: Ideal weight = 18.5 × (1.65)² to 22.9 × (1.65)² = 50.3 kg to 62.3 kg.

How to Calculate Your Ideal Weight

Your ideal weight is a range, not a single number. Any weight within the healthy BMI band (18.5–22.9 for Indians) is a healthy goal. Focus on the midpoint of the range as a practical target if you are currently overweight or obese.

• Ideal weight ranges are based on ICMR Asian BMI cutoffs (18.5–22.9)
• Weight alone does not determine health — muscle mass, body fat, and waist size also matter
• A loss of 5–10% of body weight produces significant health improvements even without reaching the ideal range
• Aim for 0.25–0.5 kg loss per week — sustainable and preserves muscle

Healthy BMI

What is a Healthy BMI — Healthy BMI Range for Indians

For Indians and South Asians, a healthy BMI is 18.5 to 22.9, as defined by the Indian Council of Medical Research (ICMR) and the WHO Expert Consultation on appropriate body-mass index for Asian populations. This is also referred to as a normal BMI for Indian adults — the range associated with the lowest health risk in South Asian populations.

What is healthy BMI for Indians? A healthy BMI — also called a normal BMI — means a score between 18.5 and 22.9 for South Asians. A BMI below 18.5 suggests underweight, which can indicate insufficient energy reserves, reduced immunity, and risk of nutritional deficiencies. A BMI of 23 and above signals increasing cardiovascular and metabolic risk for South Asians.

Important: BMI is a population-level screening tool — not a diagnosis. Athletes may have a high BMI due to muscle mass, while elderly individuals may have a healthy BMI but high body fat. Always interpret BMI in context with other health markers and consult your doctor for a personalised assessment.

Common Questions

Frequently Asked Questions