BMI Calculator — Metric & Imperial, With Healthy Range
BMI (Body Mass Index) is a quick screening number: weight relative to height. It's not a full health assessment — muscle, age and body type matter — but it's the standard starting point doctors use. Enter your height and weight in metric or imperial units to see your BMI, your category, and the healthy weight range for your height.
BMI is a screening tool, not a diagnosis — athletes and older adults should interpret it with a professional.
This tool provides general health information, not medical advice. Consult a healthcare professional for personal guidance.
How to use this tool
- Pick metric (kg/cm) or imperial (lb/ft-in) — the fields adjust automatically.
- Enter your height and current weight.
- Press Calculate to see your BMI, category and the healthy weight range for your height.
Frequently asked questions
What do the BMI categories mean?
WHO adult categories: under 18.5 = underweight, 18.5–24.9 = healthy, 25–29.9 = overweight, 30+ = obese. Some Asian populations use lower cutoffs (23 for overweight) because health risks appear at lower BMIs — many South Asian health authorities recommend the stricter scale.
Is BMI accurate for athletes and bodybuilders?
No — BMI can't tell muscle from fat. A muscular person can be \"overweight\" on BMI with very low body fat. If you train seriously, waist circumference, waist-to-height ratio and body-fat percentage are better indicators.
Does BMI apply to children?
Not with adult cutoffs. Children's BMI is assessed against age-and-sex growth percentiles. This calculator is designed for adults 18+.
Is BMI still worth using at all?
As a population screening tool, yes — it correlates with disease risk at the group level and takes ten seconds. As a personal health verdict, it's only the first data point. Trends matter more than single readings; discuss anything concerning with a doctor.
What's a healthier target: BMI or waist size?
Growing evidence favours waist-to-height ratio: keep your waist under half your height. Someone can hold a healthy BMI while carrying risky abdominal fat, which the waist measure catches.