About the BMI Calculator
Body Mass Index (BMI) is a simple screening number based on your height and weight. This calculator works in metric (kg, cm) or imperial (lb, ft/in) units and shows where you fall on the standard BMI scale.
It marks your value against the underweight, normal, overweight and obese ranges. Your measurements stay in your browser.
Worked example: 70 kg at 170 cm gives a BMI of 24.22 (kg ÷ metre², i.e. 70 ÷ 1.70²), which sits in the Normal band. The bands used are under 18.5 underweight, 18.5–25 normal, 25–30 overweight and 30+ obese. BMI is a screening number, not a medical diagnosis.