Body
Metrics
Understand your body beyond the scale — composition, healthy ranges and what the numbers actually mean.
More Body Metrics calculators
More than a number on the scale
Weight alone tells an incomplete story. These tools fill in the rest. The BMI calculator gives a quick screen of weight relative to height and your healthy weight range. The body fat calculator estimates your composition with the US Navy tape method, distinguishing fat from lean mass in a way BMI can't. And the ideal weight calculator turns the healthy BMI range into a realistic target weight for your height.
Read them together
No single metric is the whole truth. BMI flags potential concerns fast but can't see muscle; body fat shows composition but is an estimate; the ideal weight range gives direction without pretending there's one perfect number. Used together — and alongside how you feel, move and perform — they give a balanced, honest picture of your body that any one figure would miss.
Frequently asked questions
Which body metric should I track?
BMI is a quick screen, body fat percentage describes your composition, and a healthy weight range gives a realistic target. Together they tell you far more than any one number alone — especially if you are active or muscular.
Why does BMI disagree with body fat?
BMI only uses height and weight, so it cannot tell muscle from fat. Body fat percentage measures composition directly, which is why a muscular person can have a high BMI but low body fat.