Calm, source-linked explanations of the numbers behind common health calculators, and what those numbers can and cannot tell you.
Health calculators turn a few measurements into a useful starting estimate: a BMI category, a daily calorie figure, a rough water target or a body fat percentage. They use published formulas, so they are consistent and quick. They are also simplifications. None of them knows your medical history, medication, pregnancy, training or how your body differs from the averages the formulas were built on.
Treat a result as a starting point and watch the trend over weeks rather than reacting to one reading. Measure the same way each time, for example in the morning and with the same scale or tape. If a number worries you, or you have a health condition, please get personal advice from a qualified professional. Nothing on this site is medical advice.
