BMI Calculator by Age
A BMI calculator by age helps you determine healthy body mass index ranges specific to different age groups, from children to seniors. Use our free age-specific BMI calculator to understand how healthy BMI standards change throughout life stages. This tool accounts for age-related variations in body composition and provides appropriate BMI ranges for children, teenagers, adults, and elderly individuals, ensuring accurate health assessments across all age groups.
Free • Instant results • Age-specific ranges
How Age-Specific BMI Calculation Works
BMI Formula by Age Group
BMI = Weight (kg) / Height (m)²
Adults & Seniors: Standard BMI categories apply
Children 2-5: BMI percentile compared to growth charts
Children 6-19: Age and gender-specific percentiles
Seniors 65+: Slightly higher healthy BMI range (23-29)
Example Age-Specific BMI Calculation
A 12-year-old boy weighing 45 kg at 1.5m height has a BMI of 20.0. While this BMI would be normal for adults, for a 12-year-old boy, this falls in the 75th percentile, indicating healthy weight for his age group.
This demonstrates why age-specific BMI assessment is crucial for accurate health evaluation.
Benefits of Age-Specific BMI Calculation
Frequently Asked Questions
Why does BMI range change with age?
BMI ranges change because body composition varies throughout life. Children have different growth patterns, while seniors may have higher healthy BMI ranges due to muscle loss and bone density changes.
What is a healthy BMI for a 16-year-old?
For teens, healthy BMI is measured in percentiles. A healthy range is typically between the 5th and 85th percentile for their age and gender.
Is BMI accurate for elderly people?
BMI can be less accurate for seniors due to muscle loss. Many healthcare providers use slightly higher BMI ranges (23-29) for adults over 65.
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