Health

BMI Calculator: What Your Number Actually Means

What BMI is, its limitations, how to calculate it, and what the BMI categories mean for your health.

12 June 2026·5 min read·Open the tool →

What is BMI?

Body Mass Index is calculated from height and weight. Formula: BMI = weight (kg) ÷ height (m)²

BMI categories (WHO)

  • Below 18.5 — Underweight
  • 18.5 – 24.9 — Normal / Healthy
  • 25.0 – 29.9 — Overweight
  • 30.0+ — Obese

Use ToolCrix BMI Calculator — supports metric and imperial, and also estimates body fat percentage and ideal weight range.

Limitations of BMI

  • Muscle mass — athletes often have high BMI despite low body fat.
  • Age and sex — older adults and women typically have more body fat at the same BMI.
  • Ethnicity — Asian populations face higher risk at lower BMI values.
  • Fat distribution — waist circumference is a better predictor of metabolic risk.

Consult a healthcare professional. BMI is a starting point, not a diagnosis.