BMI Calculator
Calculate your Body Mass Index and see which category you fall into. BMI is a useful starting point for assessing body weight relative to height.
Your Body Mass Index (BMI) is a simple calculation that uses your height and weight to estimate whether you are in a healthy weight range. While BMI does not directly measure body fat, it correlates reasonably well with body fat levels for most people and serves as a useful screening tool.
The standard BMI categories are: Underweight (below 18.5), Normal (18.5-24.9), Overweight (25-29.9), and Obese (30+). However, BMI has limitations — it does not account for muscle mass, bone density, or fat distribution. Athletes and people with high muscle mass may have a higher BMI without having excess body fat.
A body BMI calculator for men works the same way as one for women, but the interpretation may differ. Men typically have higher muscle mass, which can push BMI up without indicating unhealthy body fat. For men who lift weights regularly, a BMI in the "overweight" range (25-29.9) may still reflect a healthy body composition. Conversely, a "normal" BMI in a sedentary man could mask low muscle mass and higher body fat percentage. This is why BMI is best used alongside body fat percentage measurements.
For a more complete picture of your body composition, pair your BMI result with our Body Fat Calculator and Visual Body Fat Estimator. If you are tracking changes over time, our Progress Photos feature gives you a fuller view of your transformation. You can also reference our height and weight chart to see how your numbers compare to population averages.
About BMI
Body Mass Index (BMI) is a simple calculation using height and weight. While it does not directly measure body fat, it is a useful screening tool for weight categories that may indicate health risks.
Note: BMI may overestimate body fat in athletes and muscular individuals, and may underestimate it in older adults or those with low muscle mass. Use it as a general reference alongside other health indicators.
BMI Categories
- Underweight: BMI less than 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obese: BMI 30 or higher
Related: For a more comprehensive health assessment, combine your BMI with our Body Fat Calculator using the Navy circumference method.
Frequently Asked Questions
What is a healthy BMI range?
A BMI of 18.5-24.9 is considered healthy for most adults. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese. These apply to adults 18-65.
Is BMI accurate for athletes?
BMI does not distinguish between muscle and fat. Athletes with high muscle mass may have an overweight BMI while having very low body fat. Use body fat percentage instead.
Does BMI apply to older adults?
For adults over 65, a BMI of 24-27 may be optimal. Slightly higher BMI can be protective against fractures and illness in older populations.
Is BMI different for men and women?
BMI uses the same formula for men and women, but women naturally have higher body fat percentages. A healthy BMI range is the same (18.5-24.9).