BMI Calculator
Calculate Body Mass Index from height and weight in metric or imperial units, see exactly where you land on the WHO weight-category scale, and get the healthy weight range for your own height.
BMI Calculator
Calculate Body Mass Index from height and weight in metric or imperial units, see exactly where you land on the WHO weight-category scale, and get the healthy weight range for your own height.
Enter your height and weight to see where you fall on the scale.
How BMI Calculator Works
Body Mass Index (BMI) is a simple screening measure that relates weight to height:
The result is compared against the World Health Organization's standard weight categories:
- Below 18.5 — Underweight
- 18.5 – 24.9 — Normal weight
- 25 – 29.9 — Overweight
- 30 and above — Obese
BMI is a quick population-level screening tool, not a diagnosis — it doesn't distinguish muscle from fat, so very muscular people can show a "high" BMI despite low body fat. See your healthcare provider for a full assessment.
Worked Example
Height: 170 cm (1.70 m)
Weight: 65 kg
BMI = 65 ÷ (1.70 × 1.70) = 65 ÷ 2.89 ≈ 22.5
A BMI of 22.5 falls in the "Normal weight" range (18.5–24.9). For someone 170 cm tall, the calculator would show a healthy weight range of roughly 53.5 kg to 72 kg.
Frequently Asked Questions
What is a healthy BMI range?
For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight range. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is classified as obese.
How is the healthy weight range calculated?
It's the weight span that keeps your BMI between 18.5 and 24.9 at your entered height, calculated instantly alongside your BMI result.
Is BMI accurate for everyone?
BMI is a useful general screening tool but has known limitations — it doesn't account for muscle mass, bone density, age, sex or fat distribution. Athletes and very muscular people, for example, can show an elevated BMI despite having low body fat. Talk to a healthcare professional for a fuller picture of your health.
Does the calculator work in both metric and imperial units?
Yes — toggle between Metric (cm/kg) and Imperial (feet-inches/lb) at the top of the calculator; your height and weight labels and inputs switch automatically.