Understanding your BMI result
Body Mass Index is a simple ratio of weight to height — your weight in kilograms divided by your height in metres squared. It gives a quick, free estimate of whether your weight sits in a healthy range for your height, which is why doctors, gyms, and insurers use it as a first-pass screening number.
What the categories mean
Under 18.5 is classed as underweight, 18.5–24.9 as a healthy weight, 25–29.9 as overweight, and 30 and above as obese (split into classes I, II, and III). This calculator also shows the exact weight range that would keep you in the healthy band for your height, in both kilograms and pounds.
BMI is a guide, not a diagnosis
BMI is a useful starting point, but it has real limits. It cannot tell muscle from fat, so very muscular athletes can read as “overweight” while being extremely fit, and it does not account for bone density, age, or where you carry weight. Treat your result as one signal among many, and speak to a healthcare professional before making decisions about your health.
Metric or imperial
Switch between metric (cm and kg) and imperial (feet, inches, and pounds) with one tap — the calculator converts everything for you, so you get the same accurate BMI either way.