Body mass index from your weight and height, in whichever units you’re used to. Enter pounds and feet/inches or kilograms and centimeters, and get your BMI, your weight category, and the healthy weight range for your height — updated live as you type.
The BMI categories
BMI divides your weight by the square of your height, which keeps the scale consistent across different body sizes. The standard categories: under 18.5 is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 and up is obesity. The calculator also shows the weight range that lands between 18.5 and 24.9 for your exact height — the practical target zone, in your chosen units.
What BMI is good for (and not)
BMI is a quick screening measure used across populations, and it’s genuinely useful as a rule of thumb. It doesn’t distinguish muscle from fat, though — athletes with high muscle mass can read overweight, and it can’t tell you where on the body fat sits, which matters metabolically. Treat the number as a starting point, not a diagnosis, and pair it with how you feel and what your doctor says.
Both unit systems compute the same result — 180 lb at 5’10” and 81.6 kg at 178 cm are the same person. Built in-house in plain JavaScript, no third-party widgets, and nothing you type leaves your device. This tool is for information only and is not medical advice.