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Calculate your BMI instantly with our free Body Mass Index calculator. Get accurate results, BMI categories, and personalized health recommendations based on WHO standards.
Our free calculator works for women, men, and adults of all ages. The BMI formula uses your weight and height to provide accurate results. Whether you need metric (kg/cm) or imperial (lbs/in) measurements, our tool supports all unit systems.
Choose between Metric (kg/cm) or Imperial (lbs/in) units. Our calculator supports both systems.
Input your weight and height accurately. For metric units, use kilograms and centimeters. The BMI formula will calculate your result automatically.
Include age and gender for more personalized interpretations and recommendations.
View your BMI value, category classification, chart position, and personalized health recommendations.
Weigh yourself at the same time of day for consistency
Ensure your scale and measuring tools are calibrated
Remember that BMI treats all body weight equally, so individuals with higher muscle density may have elevated BMI values despite having low body fat percentages
Our BMI chart shows the standard BMI ranges used by healthcare providers worldwide. This chart applies to adults, with separate considerations for women and men. The chart follows WHO standards for accurate health assessment.
Underweight
< 18.5
Normal
18.5 - 24.9
Overweight
25 - 29.9
Obese
≥ 30
Health Risks:
Health Benefits:
Health Risks:
Health Risks:
Health Risks:
Health Risks:
Beyond the standard BMI calculation, our tool provides advanced metrics. BMI Prime and Ponderal Index offer additional insights for women, men, and adults seeking comprehensive health assessment.
BMI Prime compares your BMI to the normal weight threshold (25 kg/m²). Healthcare providers use this ratio for quick health assessments. It shows how far you are from the healthy range.
The World Health Organization recognizes BMI Prime as a useful metric. It simplifies weight status interpretation for medical professionals and patients.
The Ponderal Index uses height cubed instead of squared. This makes it more accurate for very tall or short individuals. Healthcare providers recommend it when BMI may be misleading.
Medical professionals use Ponderal Index for body composition analysis. It's particularly useful for athletes and individuals with extreme heights.
While our calculator provides accurate results, understanding how BMI compares to other metrics helps users make informed health decisions. Our calorie integration and body fat comparisons offer comprehensive health insights.
| Metric | What It Measures | Accuracy | Best For | Limitations |
|---|---|---|---|---|
| BMI | Weight relative to height | General population screening | Quick health assessment, population studies | Doesn't distinguish muscle from fat |
| Body Fat % | Actual fat tissue percentage | More precise for body composition | Athletes, fitness tracking, detailed analysis | Requires specialized equipment or measurements |
Key Takeaway: Healthcare providers use BMI for quick screening, but body fat percentage provides more accurate body composition data. For athletes or muscular individuals, body fat percentage is more reliable than BMI alone. Use our body fat calculator alongside this BMI calculator for comprehensive health assessment.
| Metric | What It Measures | Health Risk Indicator | Best For | Combined Use |
|---|---|---|---|---|
| BMI | Overall body weight relative to height | General weight-related health risks | Population health screening | Use with waist circumference for comprehensive assessment |
| Waist Circumference | Abdominal fat accumulation | Cardiovascular and metabolic disease risk | Identifying visceral fat and metabolic syndrome | Complements BMI by showing fat distribution |
Key Takeaway: Medical professionals recommend using both BMI and waist circumference together. A normal BMI with high waist circumference (normal weight obesity) still indicates increased health risks. Healthcare providers use this combination for comprehensive cardiovascular risk assessment. Combine BMI results with calorie calculator and BMR calculator for complete health planning.
Use these complementary calculators alongside our BMI calculator for comprehensive health assessment. Our calorie and body fat integration help users achieve their health goals. Healthcare providers recommend combining multiple metrics for accurate health evaluation.
Calculate body fat percentage using various methods. Healthcare providers use body fat measurements alongside BMI for comprehensive health assessments. Essential for athletes and fitness enthusiasts.
Determine daily calorie needs for weight management. Medical professionals use calorie calculations to support BMI-based health goals. Works perfectly with BMI results.
Calculate your Basal Metabolic Rate. Healthcare providers use BMR alongside BMI to understand metabolic health and weight management needs. Complete your health assessment toolkit.
Calculate running pace and fitness metrics. Useful for tracking exercise goals alongside BMI monitoring.
Track pregnancy timeline and health. Healthcare providers use pregnancy-specific metrics alongside BMI for maternal health assessment.
Calculate age accurately. Age is an important factor healthcare providers consider when interpreting BMI results.
The World Health Organization defines a healthy BMI range as 18.5 to 24.9. Healthcare providers use this range to assess weight-related health risks.
However, BMI should be considered alongside other factors like muscle mass, age, and overall health status.
Yes, BMI can be misleading for athletes or very muscular individuals. Muscle tissue weighs more than fat tissue, which can skew BMI calculations.
Healthcare providers recommend additional measurements like body fat percentage for athletes. Medical professionals use body composition analysis for accurate health assessments.
For most people, checking BMI monthly is sufficient. Healthcare providers recommend focusing on long-term trends rather than daily fluctuations.
Daily fluctuations can be affected by water retention and other factors. Medical professionals use regular BMI monitoring for weight management tracking.
Consult with a healthcare professional to develop a safe weight management plan. Medical professionals can assess your health risks and create personalized strategies.
Focus on sustainable lifestyle changes including diet and exercise. The World Health Organization emphasizes gradual weight loss for long-term health benefits.
BMI Prime provides a quick ratio comparison to the normal BMI upper limit (25 kg/m²). Healthcare providers use it to simplify weight status interpretation.
Both BMI and BMI Prime are useful for different purposes. Medical professionals often use both metrics for comprehensive health assessments.
Select your preferred units (metric or imperial)
Enter your weight (in kg or lbs)
Enter your height (in cm, meters, or feet/inches)
Click 'Calculate BMI' to get your result
Review your BMI category and health recommendations
Health Screening: Quick assessment of weight status and health risks
Fitness Goals: Track progress during weight loss or muscle gain programs
Medical Consultations: Prepare information for doctor visits
Athletic Training: Monitor body composition changes during training
Pregnancy Planning: Understand pre-pregnancy weight status
Insurance Applications: Provide BMI information for health insurance
Research Studies: Calculate BMI for health research participation
Body Mass Index (BMI) is a numerical value derived from your weight and height. It's a widely-used screening tool that helps identify potential weight-related health issues. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI provides a simple, quick assessment of body weight relative to height.
BMI = weight (kg) / [height (m)]²
Example: 70 kg / (1.75 m)² = 22.86
BMI = (weight (lbs) / [height (in)]²) × 703
Example: (154 lbs / (69 in)²) × 703 = 22.75
Underweight: BMI less than 18.5 - May indicate malnutrition or other health issues
Normal Weight: BMI 18.5-24.9 - Generally associated with lowest health risks
Overweight: BMI 25-29.9 - Increased risk for health problems
Obese Class I: BMI 30-34.9 - Moderate health risk
Obese Class II: BMI 35-39.9 - High health risk
Obese Class III: BMI 40+ - Very high health risk
While BMI is a useful screening tool, it has important limitations:
For a more complete health picture, consider these measurements alongside BMI: Waist circumference, Waist-to-hip ratio, Body fat percentage, Muscle mass percentage, Blood pressure, Blood glucose levels, Cholesterol levels, and overall fitness level. Consult healthcare professionals for comprehensive health assessments.
BMI is a screening tool, not a diagnostic tool. If your BMI indicates a potential health concern, consult with a healthcare provider who can assess your overall health through additional measurements, blood tests, and personal health history. Two people with the same BMI may have very different health statuses.