How to Calculate BMI Using Metric and Imperial Units Step by Step — 2026

BMI is a population-level screening tool with reasonable accuracy for most adults. It has limitations for athletes with high muscle mass, elderly individuals with reduced muscle mass, and pregnant women. For these groups, body fat percentage and other metrics provide more accurate assessments.

Both metrics serve different purposes. BMI is useful for quick, standardized screening and comparison with population norms. Body fat percentage provides more specific information about body composition. The CDC recommends using BMI as a starting point, with body fat percentage testing for follow-up evaluation.

The CDC recommends checking BMI at least annually for adults, or more frequently during weight management programs. For children and adolescents, BMI percentile should be tracked every 3-6 months to monitor growth patterns.

Yes. Research shows that different ethnic groups have varying body composition and health risks at the same BMI level. For example, many Asian populations have higher body-fat percentages at lower BMI values, so some guidelines use lower action points (overweight at 23, obesity at 27.5).