BMI Calculators

BMILab guides

Plain-language answers to bmi calculators questions, written from the same sourced data behind BMILab. Every guide lists its sources and the date it was last updated.

Updated June 10, 2026
What does BMI actually measure — and what does it miss?
BMI is a kg/m² ratio that screens for weight-related risk by category, but it cannot distinguish muscle from fat or account for age, sex, or ethnicity.

BMILab guides

What does BMI actually measure — and what does it miss?