Fitness, body composition, training, and recovery tools.

• BMI & Body Fat Calculator
  Calculate BMI and US Navy body fat percentage from height, weight, neck, waist, and hip. See health categories.
• Running Pace Calculator
  Convert distance and time to pace. Predict race times with Riegel formula and view training zones.
• One Rep Max Calculator
  Estimate your 1RM for lifts using Epley, Brzycki, Lombardi, McGlothin, and other validated formulas.
• Sleep Cycle Calculator
  Calculate optimal bedtimes from your wake time using 90-minute sleep cycles (4–8 cycles).
• Target Heart Rate Zones
  Calculate fat-burn, cardio, and peak heart rate training zones from age and resting heart rate.
• Daily Water Intake
  Estimate your daily hydration target from weight, activity level, and environment.
• Barbell Plate Calculator
  See exact plates per side to load a target total weight on a standard bar.
• Waist-to-Hip Ratio
  Measure central obesity risk. Enter waist and hip, see ratio and health category by gender.
• Caffeine Level Tracker
  Enter intake and time. See current level, time to sleep-safe, and decay curve. Multiple doses.
• Sleep Debt Calculator
  Track missed sleep over days. See total debt, recommended catch-up, and bedtime to recover.
• Body Surface Area
  Estimate BSA in m² using common medical formulas (Mosteller, DuBois, Haycock). Live results for dosing/calculations.
• VO2 Max Estimator
  Estimate from resting HR, age, and activity level (or Cooper test).
• Ideal Weight Calculator
  Multiple formulas (Hamwi, Devine, Miller, Robinson).
• Pregnancy Due Date + Milestones
  Calculate due date from LMP and show trimester milestones.
• Medication Half-Life Tracker
  Estimate time for drug to reduce to certain level.
• Sunburn Time Estimator
  Rough time to burn based on UV index and skin type.

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