Health & fitness
Body metrics, training paces and everyday wellness math.
BMI calculator Body mass index in metric or imperial, with an honest note on its limits. BMR & TDEE calculator Resting and total daily energy expenditure using Mifflin–St Jeor. Macro calculator Split a calorie target into protein, carbohydrate and fat, in grams. Body fat percentage The US Navy tape method, plus lean mass and fat mass. Running pace calculator Pace, time and distance — solve for any one, in min/mile or min/km. One-rep max calculator Estimated 1RM from a set, plus a full percentage-of-max training table. Heart rate zones Training zones from maximum or resting heart rate (Karvonen method). Pregnancy due date Estimated due date and current week from a last period or conception date. Water intake calculator A daily fluid target from body weight, activity and climate. Caffeine half-life How much caffeine is still in you at bedtime, and when it wears off. Sleep cycle calculator Bedtimes and wake times aligned to 90-minute sleep cycles.