BMI Calculator
Calculate Body Mass Index (BMI) with metric or imperial units. Free online BMI calculator.
BMI Categories
| Category | BMI Range |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 โ 24.9 |
| Overweight | 25.0 โ 29.9 |
| Obese | โฅ 30.0 |
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a measure of body fat based on height and weight. It's calculated as weight in kilograms divided by height in meters squared (kg/mยฒ). BMI provides a simple screening method for weight categories that may lead to health problems.
How is BMI calculated?
For metric units: BMI = weight (kg) / (height (m))ยฒ. For imperial units: BMI = (weight (lb) / (height (in))ยฒ) ร 703. Our calculator handles both unit systems automatically.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is considered normal and healthy. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese. However, BMI is just one indicator and doesn't account for muscle mass, bone density, or body composition.
Is BMI accurate for everyone?
BMI is a general screening tool and may not be accurate for everyone. It doesn't distinguish between muscle and fat mass, so very muscular individuals may have a high BMI but low body fat. It may also be less accurate for older adults, athletes, and certain ethnic groups. Consult a healthcare professional for a complete health assessment.
Should I use metric or imperial units?
Either works! The result is the same. Use whichever system you're comfortable with. Metric uses kilograms and centimeters, while imperial uses pounds and inches.
Is this tool free?
Yes, completely free with no sign-up required. All calculations happen in your browser.