BMI Calculator: How to Calculate Your Body Mass Index
Calculate your BMI
Body Mass Index (BMI) is a quick, widely used way to estimate whether your weight is in a healthy range for your height. Enter your height and weight below to calculate it instantly, or use the formula further down the page to work it out by hand.
What does the result mean?
BMI splits results into four broad categories:
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5–24.9 | Normal weight |
| 25–29.9 | Overweight |
| 30 and above | Obese |
The BMI formula
| BMI = weight (kg) / height (m)² |
In imperial units, the formula is BMI = 703 × weight (lb) / height (in)².
A word of caution for lifters
BMI is only a rough screening tool, and it becomes noticeably less accurate for anyone carrying above-average muscle mass. It does not distinguish between muscle and fat, so a well-built bodybuilder at 180 cm and 90 kg will often show up as "overweight" on the BMI scale, even with a low body-fat percentage. If you train with weights regularly, treat your BMI as one data point among several — body-fat percentage and how you actually look and feel in the mirror matter far more than a single number on this scale.