Every metric on this page uses the published method a clinic or textbook would: WHO BMI categories, the Mifflin-St Jeor equation for metabolic rate, activity multipliers for TDEE, the US Navy circumference method for body fat and four classic formulas for ideal weight. Results are therefore comparable with anything a professional quotes.
Every calculator takes both unit systems — switch the units selector and enter centimetres and kilograms or inches and pounds; conversions happen internally and results show both where useful.
Population formulas describe the average body: muscular builds read 'overweight' on BMI, tape-measure body fat carries a few points of uncertainty, and calorie needs vary ±10–15% between similar people. The calculators state their methods so you can weigh the number accordingly — trends in your own results carry more signal than any single reading.
The page is ordered as a pipeline: BMI and body fat describe where you are, BMR and TDEE establish what your body spends, and the calorie deficit calculator turns a goal into a daily number and a date. The fitness category's protein and training tools pick up from there.