Fitness calculators

These are screening numbers. None of them diagnoses a condition, writes a diet, or replaces a clinician. BMI, calories, protein, and water are four different formulas that all start from body size and then go somewhere else.

BMI is kilograms divided by metres squared. At 162 cm and 58 kg it is 22.1, inside the adult band this page labels healthy (18.5 to 24.9). The bands are the common adult split. They are not children’s percentiles, and they cannot see muscle, pregnancy, or bone. Calories use Mifflin–St Jeor, then the activity factor you pick. A 35-year-old man at 170 cm and 75 kg, light activity, lands near 2,258 calories to maintain. The minus-500 line is a textbook half-kilogram a week, not a promise.

Protein multiplies kilograms by 0.8, 1.2, 1.6, or 2.0. It does not treat grams per pound. A chicken breast’s weight is not its protein grams. Water is 35 ml per kilogram, times 1, 1.15, or 1.3 for the kind of day. A heart or kidney limit from a doctor overrides that litre. Pace is time divided by distance and assumes even splits. The label says per kilometre even if you typed miles. Sleep counts 90-minute cycles plus 15 minutes to fall asleep. Real cycles are not exactly 90 minutes.