Work out obesity class instantly with clear inputs, formula shown and shareable results.
The WHO classification bands BMI at 25, 30, 35 and 40. At 105 kg and 1.72 m the BMI is 35.5 - obesity class II, needing about 1.4 kg to drop into class I and 31.1 kg to reach a BMI of 25. Even a 5-10% weight loss produces meaningful metabolic improvement well before any class boundary is crossed.
WHO classes
25 overweight, 30 class I, 35 class II, 40 class III
Weight at a target BMI
weight = target BMI x height(m)^2
These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.
The boundaries are conventions rather than biological cliffs. A 5-10% loss improves blood pressure, lipids and glycaemia regardless of class change.
No. Several Asian countries use lowered thresholds of 23 for overweight and 27.5 for obesity, reflecting risk at lower BMI.