BMI Calculator
Enter your height and weight in metric or imperial units to calculate your BMI. See your category (Underweight, Normal, Overweight, Obese) with a color-coded visual indicator and your healthy weight range.
| Category | BMI Range | Health Risk |
|---|---|---|
| Underweight | < 18.5 | Nutritional deficiency risk |
| Normal | 18.5 – 24.9 | Lowest health risk |
| Overweight | 25.0 – 29.9 | Increased risk of chronic disease |
| Obese | ≥ 30.0 | High risk of chronic disease |
How to Use the BMI Calculator
- Enter your height in centimeters or feet and inches
- Enter your weight in kilograms or pounds
- Click Calculate to see your BMI
- View your BMI category with a color-coded indicator
- Check the healthy weight range for your height
Pre-Calculated BMI Pages
Browse our pre-calculated BMI pages for instant results across 200+ height and weight combinations with detailed explanations and healthy weight ranges.
What Is BMI (Body Mass Index)?
Body Mass Index (BMI) is a numerical value calculated from a person's height and weight. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI is used as a screening tool to categorize individuals into weight status groups: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25.0–29.9), and Obese (30.0 and above). The World Health Organization (WHO) and most health organizations use these thresholds for population-level health assessments.
BMI is calculated by dividing weight in kilograms by height in meters squared (kg/m²). While BMI is a useful and widely accepted screening metric, it has notable limitations. It does not distinguish between muscle mass and fat mass, meaning muscular athletes may be classified as overweight despite having low body fat. It also does not account for fat distribution, bone density, age, sex, or ethnicity, all of which influence health risk. BMI should be considered alongside other measurements such as waist circumference, body fat percentage, and clinical assessments for a complete health picture.
Common Use Cases
Health Screening
Quickly assess whether your weight falls within a healthy range for your height as a first step in evaluating overall health status.
Fitness Goals
Track changes in your BMI over time as you work toward weight loss, muscle gain, or general fitness improvement targets.
Medical Assessments
Healthcare providers use BMI as part of routine checkups to identify patients who may benefit from further evaluation or lifestyle changes.
Health Insurance
Some insurance providers reference BMI categories when determining premiums or eligibility for certain health and life insurance policies.
BMI Calculation Tips
Measure Accurately
Use a reliable scale and measure height without shoes for the most accurate BMI calculation. Small errors in height have a large impact on the result.
Consider Body Composition
BMI does not measure body fat directly. Athletes and people with high muscle mass may have a high BMI but low body fat percentage.
Use It as a Starting Point
Combine BMI with waist circumference, body fat percentage, and blood pressure readings for a more complete picture of your health.
Check Regularly
Track your BMI periodically rather than daily. Monthly or quarterly measurements provide a clearer picture of long-term trends.
BMI Categories (WHO Classification)
| Category | BMI Range | Health Risk | Typical Action |
|---|---|---|---|
| Underweight | < 18.5 | Nutritional deficiency, weakened immunity | Consult a dietitian for weight gain plan |
| Normal | 18.5 – 24.9 | Lowest overall health risk | Maintain current healthy lifestyle |
| Overweight | 25.0 – 29.9 | Increased risk of heart disease, diabetes | Consider diet and exercise adjustments |
| Obese | >= 30.0 | High risk of chronic diseases | Seek medical guidance for weight management |