BMI Calculator
Body Mass Index, category and your healthy weight range.
Results update automatically as you type.
How to Use
- Choose Metric or Imperial units.
- Select your gender and enter your age.
- Enter your height and weight.
- Read your BMI, category, and healthy weight range instantly.
Calculation Method
BMI is your weight divided by the square of your height.
- Metric: BMI = weight (kg) / [height (m)]²
- Imperial: BMI = 703 × weight (lb) / [height (in)]²
Categories: Underweight < 18.5 · Normal 18.5–24.9 · Overweight 25–29.9 · Obese ≥ 30.
Source: World Health Organization (WHO) BMI classification
Examples
BMI = 70 / 1.75² = 22.9 → Normal weight
BMI = 703 × 200 / 69² = 29.5 → Overweight
Frequently Asked Questions
BMI does not distinguish muscle from fat, so very muscular people may show a high BMI while having low body fat. Pair it with the Body Fat Calculator for a fuller picture.
For most adults, a BMI between 18.5 and 24.9 is considered the healthy range, per WHO guidelines.
Children and teens use age- and sex-specific BMI percentiles instead of fixed thresholds. This calculator targets adults.
Tailored Versions
Same calculator, focused content for your situation.
BMI for children and teens (ages 2–19) is interpreted with CDC age- and sex-specific percentile char...
Body Mass Index for adult men, with the same WHO categories and a male-targeted explanation of what...
Body Mass Index for adult women, with the WHO categories and notes on how factors like body composit...
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Health & Fitness Disclaimer
The health and fitness calculations provided are estimates only and should not replace professional medical advice. Individual health needs vary based on medical conditions, medications, personal goals and activity level. Consult with a healthcare provider, registered dietitian, or certified fitness professional before making significant changes to your diet or exercise routine. Not medical advice.
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Last updated: May 24, 2026