Health

Calculate your body mass index in metric or imperial units. See the category breakdown and the healthy weight range for your height.

Calculate your basal metabolic rate using the Mifflin-St Jeor equation, plus daily calorie needs at five common activity levels.

Calculate the daily calories and macronutrient grams you need to lose, maintain, or gain weight. Uses Mifflin-St Jeor BMR with realistic activity multipliers.

Calculate the best bedtime or wake time based on 90-minute sleep cycles, so you wake up between cycles and feel refreshed instead of groggy.

Calculate your recommended daily water intake in ml, liters, cups, and 500 ml bottles. Adjusts for activity, climate, and pregnancy.

Estimate your due date from your last menstrual period, conception date, or ultrasound measurement. Shows current gestational age and trimester.

Estimate your one-rep max in any lift using the Epley, Brzycki, or Lombardi formula. Returns 1RM and the percentage table for training prescription.

Calculate target marathon pace per kilometer and per mile from a finish time. Returns 10k, half-marathon, and 30k splits to pace by.

Estimate body fat percentage using the US Navy circumference method. Requires height, neck, waist, and (for women) hip measurements.

Calculate how much caffeine remains in your bloodstream after any number of hours. Uses your personal caffeine half-life to estimate remaining mg.

Scale a recipe up or down by adjusting ingredient quantities to a target number of servings. Works for any unit: cups, tablespoons, grams, ounces.