BMI Calculator
Calculate your Body Mass Index (BMI) to determine if your weight is in a healthy range. Supports both metric and imperial units with instant results.
How to Use This BMI Calculator
Follow these simple steps to calculate your Body Mass Index:
- Select your preferred unit system: Metric (kg/cm) or Imperial (lbs/ft+in).
- Enter your weight in the weight field.
- Enter your height in the height field.
- Click the "Calculate BMI" button to see your result instantly.
- Review your BMI value and category on the color-coded BMI meter.
BMI Formula
Body Mass Index is calculated using the following formulas:
For example, a person weighing 70 kg and 1.70 m tall: BMI = 70 ÷ (1.70)² = 70 ÷ 2.89 = 24.2 (Normal weight).
BMI Categories (WHO Standards)
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Increased risk of nutritional deficiency |
| 18.5 – 24.9 | Normal weight | Low risk — healthy range |
| 25.0 – 29.9 | Overweight | Moderately increased risk |
| 30.0 – 34.9 | Obese (Class I) | High risk |
| 35.0 – 39.9 | Obese (Class II) | Very high risk |
| 40.0 and above | Obese (Class III) | Extremely high risk |
Examples
A woman weighing 58 kg and 165 cm tall:
BMI = 58 ÷ (1.65)² = 58 ÷ 2.7225 = 21.3
Category: Normal weight
A man weighing 95 kg and 175 cm tall:
BMI = 95 ÷ (1.75)² = 95 ÷ 3.0625 = 31.0
Category: Obese (Class I)
A person weighing 180 lbs and 5’10” (70 inches):
BMI = (180 × 703) ÷ (70)² = 126540 ÷ 4900 = 25.8
Category: Overweight
Frequently Asked Questions
What is a healthy BMI range?
A healthy BMI is generally considered to be between 18.5 and 24.9. However, BMI is just one indicator of health and doesn’t account for muscle mass, bone density, age, or gender. Athletes with high muscle mass may have a higher BMI but still be healthy.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It doesn’t distinguish between muscle and fat, so muscular individuals may be classified as overweight. It also may not be accurate for pregnant women, children, elderly, or very tall/short individuals. For a complete health assessment, consult a healthcare professional.
How do I lower my BMI?
To lower a high BMI, focus on a balanced diet rich in fruits, vegetables, lean proteins, and whole grains. Combine this with regular physical activity (at least 150 minutes of moderate exercise per week). Consult a healthcare provider or registered dietitian for personalized advice.
What is the difference between BMI and body fat percentage?
BMI is a simple ratio of weight to height, while body fat percentage measures the actual proportion of fat in your body. Body fat percentage is a more accurate indicator of body composition. Use our Body Fat Calculator for a Navy-method estimate.