BMI Calculator
Work out your body mass index (BMI), see which range you fall into and the healthy weight for your height. You can also estimate your basal metabolic rate (BMR) and daily calorie needs (TDEE).
How to use
- Enter your data in the fields — or tap “Example” to fill in a sample.
- Tap the button to calculate; the result appears below and the page scrolls to it.
- Use “Recalculate” to jump back to the inputs and try other values.
What is BMI?
Body Mass Index (BMI) is a simple screening number that relates your weight to your height. It is your weight in kilograms divided by the square of your height in metres, and it gives a quick sense of whether your weight sits in a healthy range.
How BMI is calculated
The formula is BMI = weight (kg) ÷ height (m)². Someone 1.75 m tall weighing 72 kg has a BMI of 72 ÷ (1.75 × 1.75) ≈ 23.5, which falls in the normal range.
BMI categories (WHO)
The World Health Organization groups BMI as: below 18.5 — underweight; 18.5–24.9 — normal weight; 25.0–29.9 — overweight; 30.0 and above — obesity (classes I–III). The calculator highlights your category and shows the normal-weight range for your height.
Limitations of BMI
BMI does not tell muscle from fat or account for body composition, age, sex or fat distribution. Very muscular people can read as “overweight”, while others may carry excess fat at a “normal” BMI. Treat it as a starting point, not a diagnosis — for a full picture, consult a healthcare professional.