BMI — strengths, limits and what to do next
Body Mass Index is a quick screening tool that compares your weight to your height. The classic formula (kg / m²) was designed for population statistics and remains the most used metric worldwide.
The New BMI (Trefethen, 2013) uses an exponent of 2.5 instead of 2 to correct the bias against tall people (who look heavier) and short people (who look lighter). Both values are shown side-by-side.
BMI does not separate fat from muscle. Athletes can be 'overweight' by BMI while having very low body fat. Pair BMI with the Body Fat and Ideal Weight calculators for a fuller picture.
Use the healthy range row to plan a target. A safe rate of change is 0.25–0.5 kg/week — feed that into the Calorie Calculator to set your daily intake.