BMI Calculator (Body Mass Index)
Calculate your Body Mass Index (BMI) from height and weight. Understand your BMI category and limitations.
💪 Health📐 BMI = Weight (kg) / Height (m)^2
Height (feet)
Height (inches)
Weight (pounds)
Age (optional)
Please enter valid values.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| BMI Calculator (Body Mass Index) | BMI = Weight (kg) / Height (m)^2 | BMI score |
Step-by-Step Examples
Example 1
5ft10 185lbs
5 ft 10 in, 185 lbs.
- Height = 1.778m | Weight = 83.9kg
- BMI = 83.9/3.162 = 26.5 (Overweight)
- Healthy: 129-174 lbs
✓ BMI 26.5 - Overweight
Example 2
5ft4 130lbs
5 ft 4 in, 130 lbs.
- Height = 1.626m | Weight = 59.0kg
- BMI = 22.3 (Normal weight)
- Healthy: 108-145 lbs
✓ BMI 22.3 - Normal weight
Example 3
6ft2 220lbs
6 ft 2 in, 220 lbs.
- Height = 1.880m | Weight = 99.8kg
- BMI = 28.2 (Overweight)
✓ BMI 28.2 - Overweight
Real-World Applications
Fitness
Track health progress alongside other metrics.
Healthcare
Initial screening tool used by healthcare providers.
Life Insurance
One factor in insurance risk assessments.
Research
Population-level obesity trend tracking.
Common Mistakes to Avoid
⚠️
BMI as a definitive health measure
BMI does not distinguish muscle from fat; a muscular athlete may show 'overweight' BMI despite excellent health.
⚠️
Ignoring other health metrics
BMI is most useful alongside waist circumference, blood pressure, and cholesterol, not alone.
⚠️
Using adult BMI for children
Children use BMI-for-age percentiles, not adult categories.
Frequently Asked Questions
Healthy BMI range? ▾
Under 18.5: Underweight. 18.5-24.9: Normal. 25-29.9: Overweight. 30+: Obese.
BMI accurate for athletes? ▾
No. Muscle is denser than fat; a muscular athlete may show high BMI despite low body fat. DEXA scan is more accurate.
BMI limitations? ▾
Doesn't distinguish fat from muscle, ignores fat distribution, and risk thresholds may differ by ethnicity.
What is morbid obesity BMI? ▾
BMI 40+. Class 1 obese: 30-34.9. Class 2: 35-39.9. Class 3 (morbid): 40+.
Better than BMI for body fat? ▾
Waist circumference, waist-to-hip ratio, body fat percentage by DEXA scan or hydrostatic weighing.