BMI Calculator
Body mass index & healthy range
How to Use the BMI Calculator
Our BMI (Body Mass Index) calculator helps you determine if your weight is in a healthy range based on your height. Simply enter your height and weight to get your BMI score, category, and healthy weight range.
Understanding BMI Categories
- Underweight: BMI below 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obese: BMI 30 or higher
Limitations of BMI
While BMI is a useful screening tool, it 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, gender, ethnicity, or body composition. For a deeper understanding, read our guide on Understanding BMI and Body Composition.
Your Health Journey
Pair your BMI result with our calorie calculator to understand your daily energy needs. Whether you want to lose weight, maintain, or build muscle, knowing your TDEE is essential for reaching your goals.
When to Consult a Doctor
If your BMI falls outside the normal range, consider consulting a healthcare provider. They can perform additional assessments and provide personalized recommendations for achieving and maintaining a healthy weight.
Frequently Asked Questions
BMI = weight (kg) / height (m)^2, or for pounds/inches: BMI = (weight x 703) / height^2. For example, 150 lbs at 5'8" (68 inches): (150 x 703) / (68 x 68) = 22.8 BMI. Our calculator handles both imperial and metric units.
A BMI of 18.5-24.9 is considered normal weight. Under 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese. However, BMI does not account for muscle mass, age, or body composition, so it is just one health indicator.
BMI often overestimates body fat in muscular individuals since muscle weighs more than fat. A fit athlete with significant muscle mass may have an "overweight" BMI while having low body fat. Body fat percentage is more accurate for athletes.
Healthy weight ranges vary. For a 5'6" person: 115-154 lbs is normal BMI range. For 5'10": 129-174 lbs. These are guidelines - individual factors like muscle mass, bone density, and body composition matter. Consult healthcare providers.
Standard BMI uses the same formula regardless of age or gender. However, women typically have more body fat than men at the same BMI, and older adults may have more body fat than younger adults. Adjusted calculations exist for children.
Higher BMI correlates with increased risk of heart disease, type 2 diabetes, high blood pressure, sleep apnea, and certain cancers. Even modest weight loss (5-10% of body weight) can significantly reduce these risks.