Health.

Body Mass Index for adults, with WHO category interpretation.

Basal Metabolic Rate via Mifflin-St Jeor — calories your body burns at rest.

Total Daily Energy Expenditure — daily calories needed to maintain, lose, or gain weight.

US Navy method — body fat percentage from tape measurements.

Ideal body weight ranges via Devine, Robinson, and Miller formulas.

Daily protein, carb, and fat targets from a calorie goal.

Daily protein target from body weight and activity level.

Daily carbohydrate target from calorie intake and diet style.

Estimate lean body mass (fat-free mass) using Boer, James, and Hume formulas.

Calories burned in an activity using MET values and body weight.

Convert between pace, speed, distance, and time for running or cycling.

Estimate your 1-rep max from a submaximal set using Epley, Brzycki, and Lombardi formulas.

Estimate due date from last menstrual period (Naegele's rule).

Estimate fertile window from cycle start date.

Daily water target based on body weight and activity.

Target heart rate zones for training (Karvonen method).

IOM-recommended weight gain during pregnancy based on pre-pregnancy BMI.

Estimate conception date from due date or last menstrual period.

Predict next periods, ovulation, and fertile window.

Estimate blood alcohol concentration using the Widmark formula.

Calculate body surface area using Du Bois, Mosteller, or Haycock formulas.

Weight range for a healthy BMI (18.5–24.9) at a given height.

Daily calorie target to reach a weight goal within a timeframe.

Waist-to-hip ratio and associated health risk category.

Financial cost of smoking including 10-year opportunity cost at 7% return.

Track daily caffeine intake vs the 400 mg FDA guideline.

Convert step count to calories burned and distance walked.

Detailed training zones using percent-of-max or Karvonen (heart-rate reserve).