kg
cm
Calculate your Body Mass Index instantly
Get your BMI calculated immediately with detailed category information.
Your data stays in your browser. Nothing is stored or transmitted.
Use kilograms/centimeters or pounds/feet - whatever you prefer.
No signup, no limits, no hidden fees. Calculate BMI anytime.
See exactly where you fall on the BMI scale with our visual indicator.
Get your ideal weight range based on your height.
Body Mass Index (BMI) is a simple measure that uses your height and weight to estimate if your weight is healthy. It's calculated by dividing your weight in kilograms by your height in meters squared (kg/m²). BMI is widely used by healthcare professionals as a screening tool for weight categories.
BMI is calculated using the formula: BMI = weight (kg) / height² (m²). For example, if you weigh 70 kg and are 1.75 m tall: BMI = 70 / (1.75 × 1.75) = 22.9. Our calculator does this math instantly for you in both metric and imperial units.
A BMI calculator takes your height and weight, converts them to metric units if needed, then applies the formula: weight ÷ height². It instantly categorizes your result into underweight, normal, overweight, or obese based on WHO standards.
BMI works by comparing your weight relative to your height. The resulting number indicates whether you're in a healthy weight range. Higher BMI suggests more body mass for your height, though it doesn't distinguish between muscle and fat.
A BMI between 18.5 and 24.9 is considered normal or healthy weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is considered obese. These categories are defined by the World Health Organization (WHO).
A good BMI falls within the normal range of 18.5-24.9. However, the "ideal" BMI varies based on factors like muscle mass, bone density, and overall health. Most health professionals recommend staying within this range while considering individual circumstances.
For optimal health, aim for a BMI between 18.5 and 24.9. Studies suggest that a BMI around 21-22 may be associated with the lowest health risks for many adults. However, focus on overall health rather than a specific number.
A BMI of 30 or higher is classified as obese by the World Health Organization. Obesity is further categorized: Class I (30-34.9), Class II (35-39.9), and Class III/Severe (40+). Higher classes indicate greater health risks.
BMI is a useful screening tool but has limitations. It doesn't distinguish between muscle and fat mass, so athletes may have a high BMI despite being healthy. It also doesn't account for age, sex, ethnicity, or fat distribution. For a complete health assessment, consult a healthcare professional.
While BMI has been used since the 1800s, it remains a useful quick screening tool. However, modern medicine recognizes its limitations and often supplements BMI with waist circumference, body fat percentage, and other health markers for a complete picture.
BMI calculators provide accurate mathematical results, but the BMI measure itself has limitations. Trust the calculation, but understand that BMI is just one indicator of health. Consider it alongside other factors like muscle mass, fitness level, and overall wellbeing.
No, BMI calculators don't differentiate between muscle and fat. Muscle is denser than fat, so muscular people may have a "overweight" BMI despite having low body fat. For athletes and active individuals, body fat percentage is a better metric.
The BMI formula stays the same regardless of age for adults (20+). However, BMI interpretation may vary with age. Older adults may benefit from slightly higher BMI ranges (23-28), as some research suggests this may be protective in later life.
The BMI formula and categories are the same for adult men and women. However, women typically have more body fat than men at the same BMI. For more accurate body composition assessment, other methods like body fat percentage may be more informative.
BMI may not be accurate for athletes and muscular individuals. Since muscle weighs more than fat, a muscular person may have a high BMI while having low body fat. Athletes should consider body fat percentage measurements for more accurate assessment.
A person's BMI is calculated by dividing their weight in kilograms by their height in meters squared. In imperial units: (weight in pounds × 703) ÷ (height in inches)². Our calculator handles both unit systems automatically.
Enter your height and weight in our calculator to find out. If your BMI is 25-29.9, you're overweight. The calculator also shows your healthy weight range, so you can see exactly how many pounds or kilograms you'd need to lose to reach a healthy BMI.
Use our BMI calculator to check. Enter your height and weight, and it will instantly show your BMI and category. A BMI of 30 or higher indicates obesity. The visual scale makes it easy to see where you fall.
BMI doesn't directly determine calorie needs - that depends on age, activity level, and goals. However, if your BMI indicates overweight/obesity, a calorie deficit helps. Consult a nutritionist for personalized calorie recommendations.
Your BMI indicates which weight category you fall into: Underweight (BMI < 18.5) may indicate malnutrition. Normal (18.5-24.9) suggests healthy weight. Overweight (25-29.9) indicates increased health risks. Obese (≥30) indicates significantly increased health risks.
A healthy weight is one that gives you a BMI between 18.5 and 24.9. Our calculator shows you the healthy weight range for your specific height. For example, for someone 170 cm tall, a healthy weight range is approximately 53-72 kg.
Yes! Our BMI calculator is 100% free with no limits. Calculate your BMI as many times as you want, track your progress, and share with others - all without signing up or paying anything.