Body Mass Index (BMI) is one of the most widely used health screening tools — and also one of the most misunderstood. Here's how to actually interpret your result.
How BMI is calculated
BMI compares your weight to your height using a simple formula: weight (kg) divided by height (m) squared. It was designed as a population-level screening tool, not an individual diagnosis.
- Below 18.5 — Underweight
- 18.5–24.9 — Normal weight
- 25–29.9 — Overweight
- 30 and above — Obesity range
BMI doesn't distinguish between muscle and fat, so athletes and very muscular individuals often score 'overweight' despite low body fat percentages.
What to look at alongside BMI
Waist circumference, body fat percentage, and overall activity level all give a fuller picture. Use BMI as one data point among several, not the final word on your health.
PrimeCalculator Editorial Team
Calculator & Finance Writers