Calculate your Body Mass Index instantly. Supports metric and imperial units — see your BMI category and ideal weight range.
kg
cm
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UnderweightNormalOverweightObese
--Ideal weight range
--Weight to ideal
--Your BMI
18.5–24.9Healthy BMI range
Category
BMI Range
You
Underweight
Below 18.5
Normal weight
18.5 – 24.9
Overweight
25 – 29.9
Obese
30 and above
🎯
Your healthy weight range
Based on your height
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⚠️ BMI is a screening tool only and does not diagnose health conditions. Factors like muscle mass, age, and ethnicity affect interpretation. Always consult a qualified healthcare professional for medical advice.
How is BMI calculated?
BMI (Body Mass Index) is calculated by dividing your weight by the square of your height. It was developed as a simple, population-level screening tool. The WHO uses BMI to classify weight categories for adults aged 18 and over.
May indicate nutritional deficiency. Consult a doctor if concerned about low body weight.
🟢 Normal (18.5–24.9)
Associated with the lowest risk of weight-related health conditions in most adults.
🟡 Overweight (25–29.9)
Increased risk of type 2 diabetes, high blood pressure and heart disease.
🔴 Obese (30+)
Significantly elevated risk of serious health conditions. Medical guidance is recommended.
Frequently asked questions
What is a healthy BMI range?
A healthy BMI is between 18.5 and 24.9 according to the World Health Organisation (WHO). Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese.
How is BMI calculated?
BMI = weight (kg) ÷ height² (m²). For imperial: BMI = (weight in lbs ÷ height² in inches) × 703. Both formulas produce the same result — this calculator handles the conversion automatically.
Is BMI accurate for athletes and muscular people?
Not always. BMI cannot distinguish between fat and muscle. A heavily muscular athlete may have a high BMI despite very low body fat. For a more complete picture, consider body fat percentage measurements.
Does BMI work the same for men and women?
The same BMI scale is applied to both sexes, but women naturally carry more body fat than men at the same BMI. Some health professionals use adjusted guidelines. This calculator shows standard WHO BMI for adults.
What is my ideal weight according to BMI?
After calculating, the tool shows your ideal healthy weight range — the weight range that would put you in the "Normal" BMI category (18.5–24.9) for your specific height.