BMI Calculator (Calculate Your Body Mass Index)
Your BMI Result
BMI Classification
- Underweight: BMI < 18.5
- Normal weight: BMI 18.5–24.9
- Overweight: BMI 25–29.9
- Obesity: BMI ≥ 30
What does this mean?
Your Healthy Weight Range
Health Risk Assessment
Additional Health Metrics
Waist-Hip Ratio
Ideal Weight by Different Formulas
BMI Categories Chart
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Increased risk of nutritional deficiencies and osteoporosis |
| 18.5 - 24.9 | Normal Weight | Lowest risk of health problems |
| 25.0 - 29.9 | Overweight | Increased risk of heart disease, stroke, and type 2 diabetes |
| 30.0 - 34.9 | Obese Class I | High risk of heart disease, stroke, type 2 diabetes |
| 35.0 - 39.9 | Obese Class II | Very high risk of health problems |
| 40.0 and above | Obese Class III | Extremely high risk of serious health problems |
Personalized Advice
References
- World Health Organization (WHO) BMI classification
- National Institutes of Health (NIH)
- Centers for Disease Control and Prevention (CDC)
Disclaimer: This calculator provides an estimate only and should not replace medical advice. BMI has limitations and doesn't account for factors like muscle mass, bone density, overall body composition, and racial and sex differences.
BMI Calculator for Children and Teens (2-19 years)
This calculator is specifically designed for children and teens aged 2-19 years. BMI is calculated differently for children and interpreted based on percentiles for age and gender.
Child BMI Result
What does this mean?
Healthy Range for Your Child
Children's BMI Percentile Chart
| Percentile Range | Weight Status Category | Interpretation |
|---|---|---|
| Below 5th percentile | Underweight | Child may not be getting adequate nutrition for growth and development |
| 5th to below 85th percentile | Healthy Weight | Child's weight is appropriate for their height, age, and gender |
| 85th to below 95th percentile | Overweight | Child may be at risk for developing obesity-related health problems |
| 95th percentile or above | Obese | Child has excess body fat and is at higher risk for health problems |
Source: Centers for Disease Control and Prevention (CDC)
Understanding Children's BMI
For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age. Growth patterns differ between boys and girls and change as children grow older.
Unlike adult BMI, children's BMI is compared to percentiles of other children of the same age and sex, rather than fixed thresholds. This is why BMI results are given as percentiles rather than absolute BMI values.
Recommendations
Disclaimer: For children and teens, BMI is age- and sex-specific and is often expressed as a percentile. This calculator provides an estimate based on CDC growth charts and should not replace medical advice from your child's pediatrician.
BMI Calculator for Pregnancy
Important: Pre-pregnancy BMI is used to determine weight gain recommendations during pregnancy. This calculator is designed to calculate your BMI based on your pre-pregnancy weight.
Pre-Pregnancy BMI Result
BMI Classification
- Underweight: BMI < 18.5
- Normal weight: BMI 18.5–24.9
- Overweight: BMI 25–29.9
- Obesity: BMI ≥ 30
What does this mean?
Recommended Weight Gain During Pregnancy
Your Weight Gain Progress
Pregnancy Weight Gain Chart
| Pre-Pregnancy BMI | BMI Category | Recommended Total Weight Gain | Rate of Weight Gain in 2nd and 3rd Trimesters* |
|---|---|---|---|
| Below 18.5 | Underweight | 28-40 lbs (12.5-18 kg) | 1-1.3 lbs (0.5-0.6 kg) per week |
| 18.5 - 24.9 | Normal Weight | 25-35 lbs (11.5-16 kg) | 0.8-1 lb (0.4-0.5 kg) per week |
| 25.0 - 29.9 | Overweight | 15-25 lbs (7-11.5 kg) | 0.6-0.7 lb (0.3 kg) per week |
| 30.0 and above | Obese | 11-20 lbs (5-9 kg) | 0.4-0.6 lb (0.2-0.3 kg) per week |
Weight gain in the first trimester is typically 1-4.4 lbs (0.5-2 kg) total.
Source: Institute of Medicine (IOM) and American College of Obstetricians and Gynecologists (ACOG)
Recommendations
Disclaimer: This calculator provides general recommendations based on guidelines from the Institute of Medicine. Individual needs may vary. Always consult with your healthcare provider for personalized advice during pregnancy.
