BMI Calculator
Calculate your Body Mass Index (BMI) with our free calculator. Find your healthy weight range, understand your results, and get personalized recommendations.
Body Mass Index (BMI) is a widely used screening tool that estimates body fat based on height and weight. While not a diagnostic measure, it helps identify weight categories that may lead to health risks and serves as a starting point for conversations with healthcare providers.
Examples
Example 1: Normal Weight
A person who is 5'10" (178 cm) and weighs 160 lbs (73 kg) has a BMI of 23.0, which falls in the "Normal" category.
Example 2: Overweight
A person who is 5'6" (168 cm) and weighs 180 lbs (82 kg) has a BMI of 29.1, which falls in the "Overweight" category.
Example 3: Understanding Healthy Range
For someone 5'8" tall, the healthy weight range (BMI 18.5-24.9) is approximately 122-164 lbs (55-74 kg).
BMI Categories and Health Risk
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Increased risk of nutritional deficiency |
| 18.5 - 24.9 | Normal | Lowest health risk |
| 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+ | Obese Class III | Extremely high risk |
Frequently Asked Questions
Is BMI accurate?
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, age, sex, or fat distribution. Athletes may have a high BMI due to muscle mass without being overweight.
What is a healthy BMI?
According to WHO standards, a healthy BMI is between 18.5 and 24.9. However, ideal BMI can vary based on factors like age, sex, ethnicity, and body composition.
How can I lower my BMI?
To lower your BMI, focus on a balanced diet with a calorie deficit, regular physical activity (both cardio and strength training), adequate sleep, and stress management. Consult a healthcare professional for personalized advice.
BMI vs body fat percentage?
BMI estimates whether you are underweight, normal, or overweight based on height and weight. Body fat percentage measures actual fat content. Body fat percentage is more accurate but requires specialized equipment.
Should I worry about my BMI?
BMI is just one health indicator. If your BMI falls outside the normal range, consider getting a comprehensive health assessment including blood pressure, cholesterol, and blood sugar levels.
Is BMI different for children?
Yes, BMI for children (ages 2-20) is interpreted using age and sex-specific percentiles (CDC growth charts) rather than fixed categories, as body composition changes with growth.
Related Information
BMI Limitations: BMI may overestimate body fat in athletes and muscular individuals, and underestimate it in older people who have lost muscle mass. Consider complementary measures like waist circumference and body fat percentage.
Key Terms
- BMI (Body Mass Index)
- A numerical value calculated from height and weight, used to screen for weight categories that may indicate health risks.
- Underweight
- A BMI below 18.5, which may indicate insufficient nutrition or an underlying health condition.
- Overweight
- A BMI between 25.0 and 29.9, indicating excess body weight that may increase health risks.
- Obese
- A BMI of 30.0 or higher, associated with significantly increased risk of chronic diseases.
- Waist Circumference
- A measurement around the waist used alongside BMI to assess abdominal fat and associated health risks.
Sources
- About Adult BMI — Centers for Disease Control and Prevention (CDC)
- Body Mass Index (BMI) — World Health Organization (WHO)
Result
23.0
- BMI
- 23
- Category
- Normal
- Category Color
- #22c55e
- Healthy BMI Range
- 18.5 - 24.9
Related Calculators
Quick Tips
- •Use BMI as a starting point, not a final diagnosis — pair it with waist circumference and body fat measurements for a fuller picture.
- •Athletes and people with high muscle mass should consider body fat percentage calculators instead.
- •Track BMI changes over time rather than focusing on a single reading.
- •Consult a healthcare provider before making significant diet or exercise changes based on BMI alone.