Calculate your Body Mass Index (BMI) instantly. Find out if you're in a healthy weight range based on your height and weight — results in both metric and imperial units.
<18.5Normal
18.5-24.9Overweight
25-29.9Obese
30+
How to Use the BMI Calculator
- Choose your preferred unit system: Metric (cm, kg) or Imperial (feet, lbs)
- Enter your height and weight
- Click "Calculate BMI" to see your result and weight category
- Review your healthy weight range and where you fall on the BMI scale
BMI Categories Explained
- Underweight — BMI below 18.5. May indicate insufficient body weight for height.
- Normal Weight — BMI 18.5 to 24.9. Considered a healthy weight range for most adults.
- Overweight — BMI 25 to 29.9. Slight excess weight, may be a risk factor for some conditions.
- Obese — BMI 30 and above. Associated with higher risk of health issues.
How BMI Is Calculated
BMI compares your weight to your height. The standard formula is:
BMI = weight (kg) / height² (m²)
For imperial units: BMI = (weight in lbs × 703) / height² (inches²)
Why Calculate Your BMI?
- Quick health screening — A fast way to check if your weight may be a health concern
- Track progress — Monitor changes in body weight over time
- Goal setting — Set realistic weight goals based on your healthy range
- Medical and insurance use — BMI is widely used by doctors and insurers
- Motivation — Visualizes where your weight stands relative to norms
Limitations of BMI
- Does not distinguish between muscle and fat — athletes may show high BMI despite being healthy
- Does not account for body fat distribution
- Less accurate for children, elderly, pregnant women, or very tall/short individuals
- Does not consider bone density or ethnic differences
For a complete picture of your health, always consult a qualified healthcare professional.
Frequently Asked Questions
Is BMI accurate for everyone?
BMI is a useful screening tool but is not a direct measure of body fat. It may be less accurate for athletes, elderly people, pregnant women, and certain ethnic groups. Always consult a doctor for personalized advice.
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. Individual health factors should always be considered alongside BMI.
Should children use this BMI calculator?
This calculator is designed for adults aged 18 and over. Children and teens require a different BMI scale based on age and sex, typically calculated by a pediatrician.
Is my data saved?
No. All calculations happen entirely in your browser. We do not store, transmit, or log any health information.
How often should I check my BMI?
Once every 1-3 months is enough to track healthy weight changes. Daily checks are not necessary.