MicroCalculatorsBMI Calculator
Calculate Body Mass Index: BMI = weight(kg) ÷ height(m)². Ranges: <18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obese.
BMI Calculator — FAQ
- Does muscle mass affect BMI?
- Yes. Athletes can have high BMI from muscle, not fat. BMI doesn't distinguish.
- Is BMI useful for athletes?
- Less so. Body fat or waist-to-hip may be better for muscular people.
- Are BMI ranges different for men and women?
- No. Same ranges. But body composition differs; waist measurement adds context.
What Is BMI?
Body Mass Index (BMI) is weight in kg divided by height in metres squared. It's a screening tool for weight categories: underweight (<18.5), healthy (18.5–24.9), overweight (25–29.9), obese (30+). It doesn't distinguish muscle from fat, so athletes may have high BMI despite being fit.
Use BMI as a rough guide, not a definitive health measure. Combine with waist measurement or body fat for better context. Discuss results with your doctor.
People Also Ask
- What is a healthy BMI range?
- How do I calculate my BMI?
- Is BMI accurate?
Want to learn more?
Read our in-depth guide: BMI Chart by Age: What's Actually a Healthy BMI? — age-adjusted ranges, BMI limitations, and when to use body fat percentage instead.
Last updated: February 2026