“Healthy BMI” usually means the 18.5–24.9 range for adults aged 20 and older. That band comes from decades of epidemiology—not from a single ideal weight for every person.
WHO-style cutoffs (most countries)
- Underweight: < 18.5
- Healthy / normal: 18.5 – 24.9
- Overweight: 25.0 – 29.9
- Obesity: ≥ 30.0
These apply to non-pregnant adults. They do not apply to children—pediatric BMI uses age and sex percentiles.
Asian adjustment
Some health authorities recommend overweight classification from 23.0 and obesity from 27.5 for Asian populations, reflecting earlier average onset of cardiometabolic risk. If this applies to you, discuss interpretation with a clinician familiar with your background.
Older adults
Slightly higher BMI (low overweight range) sometimes correlates with better outcomes in adults over 65, partly because low weight can reflect muscle loss. BMI alone is a weak tool in this group.
What “healthy” does not mean
A BMI inside the normal range does not guarantee good diet, fitness, blood pressure, or mental health. Conversely, overweight BMI does not automatically mean poor health. Habits and clinical markers matter.
Check your BMI
BMI Calculator (on IntermittFast—no third-party redirect). Then read BMI Category Guide and How Accurate Is BMI?
For behavior-focused fat loss: Sustainable Weight Loss Habits, Start Here, Tools.