Calculate your Body Mass Index instantly using metric (kg & cm) or imperial (lbs & inches) units. Includes BMI chart and health ranges.
Your BMI
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UnderweightNormalOverweightObese
BMI Reference Ranges
Category
BMI Range
Health Risk
Underweight
< 18.5
Nutritional deficiency risk
Normal weight
18.5 – 24.9
Lowest risk range
Overweight
25.0 – 29.9
Moderate risk
Obese (Class I)
30.0 – 34.9
High risk
Obese (Class II+)
≥ 35.0
Very high risk
⚠️ BMI is a general screening tool and does not account for muscle mass, bone density or individual health conditions. Consult a healthcare professional for personalized advice.
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Free Online BMI Calculator
Our free BMI calculator helps you find out your Body Mass Index instantly — just enter your height and weight and get your result in seconds. BMI is a widely used screening tool that gives a general indication of whether you are underweight, at a healthy weight, overweight or obese based on your height and weight ratio.
The calculator supports both metric units (kg and cm) and imperial units (lbs and inches), so it works for everyone regardless of where you are in the world. Results include your BMI score, which category you fall into, and what a healthy weight range looks like for your height.
📏 Metric & Imperial
Works with kg/cm or lbs/inches — switch between units instantly.
📊 Full Category Range
Shows Underweight, Normal, Overweight and Obese ranges with your position.
🎯 Healthy Weight Range
Tells you the ideal weight range for your specific height.
⚡ Instant Result
No button needed — BMI updates as you type height and weight.
How to Calculate Your BMI
1
Choose your units
Select Metric (kg and cm) or Imperial (lbs and inches) depending on your preference.
2
Enter your height
Type your height in centimetres or feet and inches. The result updates instantly.
3
Enter your weight
Type your current weight in kilograms or pounds.
4
Read your result
Your BMI score appears instantly with your category, a visual scale, and your healthy weight range.
BMI Categories (WHO Standard)
Under 18.5 — Underweight
18.5 – 24.9 — Normal (Healthy) weight
25.0 – 29.9 — Overweight
30.0 and above — Obese
Frequently Asked Questions
Is BMI an accurate measure of health?
BMI is a useful general screening tool, but it has limitations. It doesn't directly measure body fat percentage — a very muscular person may have a high BMI while having very little fat. It also doesn't account for age, gender, ethnicity or where fat is distributed in the body. BMI is best used as a starting point for health assessment, not a definitive diagnosis. Always consult a healthcare professional for personalised advice.
What is a healthy BMI for adults?
For most adults aged 18–65, the World Health Organization (WHO) considers a BMI of 18.5 to 24.9 as the healthy range. However, research suggests that for people of Asian descent, the healthy range may be slightly lower (18.5–22.9) as health risks can occur at lower BMI values in these populations.
Can I use this BMI calculator for children?
No — BMI works differently for children and teenagers. For people under 18, BMI is interpreted using age- and sex-specific percentile charts rather than fixed adult categories. This calculator is designed for adults only. For children's BMI, consult a paediatrician or use a dedicated children's BMI calculator.
What is the BMI formula?
BMI is calculated as weight (kg) divided by height (m) squared. For example, a person weighing 70 kg at 1.75 m height has a BMI of 70 ÷ (1.75 × 1.75) = 22.9. In imperial units, the formula is weight (lbs) × 703 ÷ height (inches) squared.
Is my health data stored or shared?
No — all calculations happen entirely in your browser. Your height, weight and health information is never sent to any server, never stored and never shared with anyone. The tool has no data collection of any kind.
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