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BMI Calculator
Calculate your Body Mass Index in metric or imperial units, see which category you fall into, and find your healthy weight range.
BMI Categories
Underweight
Below 18.5
Normal
18.5 – 24.9
Overweight
Overweight 25.0 – 29.9
Obese
30.0 and above
About BMI
What is BMI?
Body Mass Index is a simple screening measure calculated from weight and height, used as a general indicator of whether weight falls in a healthy range.
Healthy Weight Range
The weight range corresponding to a BMI of 18.5–24.9 for your specific height — a common reference point for a healthy target.
Limitations
BMI doesn't distinguish between muscle and fat, so athletes or very muscular individuals may show a high BMI despite low body fat.
Not a Diagnosis
MI is a screening tool, not a diagnostic one — always consult a healthcare professional for a full assessment of your health.
Frequently Asked
Questions
1. How is BMI calculated?
BMI is calculated as weight in kilograms divided by height in meters squared: BMI = weight (kg) ÷ height (m)². For imperial units, the formula is BMI = 703 × weight (lb) ÷ height (in)².
2. Is BMI accurate for everyone?
BMI is a useful population-level screening tool but has known limitations for individuals — it doesn’t account for muscle mass, bone density, body composition, age, or sex. Athletes, older adults, and pregnant individuals may get misleading results.
3. What is a healthy BMI range?
According to WHO guidelines, a BMI between 18.5 and 24.9 is generally considered a healthy weight range for most adults. Below 18.5 is classified as underweight, 25–29.9 as overweight, and 30 or above as obese.
4. Should I use BMI alone to judge my health?
No. BMI is best used alongside other measures like waist circumference, body fat percentage, and overall fitness. It’s a starting point for a conversation with a healthcare provider, not a complete picture of health.
5. Is my data private?
Yes. All calculations run entirely in your browser using JavaScript. Nothing you enter — your weight or height — is ever sent to any server.