Health & Fitness Calculators

Each tool here uses the published formula behind it — Mifflin-St Jeor for calories, WHO and regional cutoffs for BMI, Navy and Army methods for body fat, Karvonen zones for training — and says so, along with the limits of what a formula can tell you. Nothing you enter leaves the browser, which matters for health data. Use them to set a calorie target, plan protein intake, check a blood-pressure or cholesterol category, or pace a race. They inform decisions; your clinician makes the medical calls.