Health calculators
BMI, calorie, and other health-related calculators for adults.
- BMI Calculator Calculate your BMI (body mass index) from height and weight. Includes the WHO category bands, what BMI actually measures, and where it breaks down.
- BMI Calculator (Metric) Calculate BMI from height in centimeters and weight in kilograms. Uses the metric formula kg ÷ m² with the WHO category bands and interpretation notes.
- BMR Calculator Estimate your basal metabolic rate (BMR) using the Mifflin-St Jeor equation. Enter age, sex, height, and weight to see calories burned at rest.
- Body Fat Calculator Estimate body fat percentage using the US Navy circumference method. Enter sex, height, neck, waist, and (for women) hip measurements for an estimate.
- Calorie Calculator Estimate your daily calorie needs (TDEE) based on age, sex, weight, height, and activity. Includes maintenance, weight-loss, and muscle-gain targets.
- Calorie Deficit Calculator Free calorie deficit calculator. Target calorie intake for weight loss. Subtract a daily deficit from your TDEE to see weekly and monthly fat loss.
- Ideal Weight Calculator Estimate your ideal body weight using the Devine formula. Enter height and sex to see a target weight range used by clinicians for medication dosing.
- Macro Calculator Split a daily calorie target into protein, carb, and fat grams using your chosen macro ratio. Useful for IIFYM, cutting, bulking, and meal prep planning.
- Target Heart Rate Calculator Calculate your max heart rate and training zones from age. See your fat-burn (50-70%) and cardio (70-85%) zones in beats per minute for safer cardio.
- TDEE Calculator Calculate your Total Daily Energy Expenditure (TDEE) in metric units using the Mifflin-St Jeor BMR formula and your activity level. Get maintenance calories.
- Water Intake Calculator Estimate your daily water needs based on body weight and exercise. Enter your weight in pounds and exercise minutes for a baseline ounce-per-day estimate.