Health, Fitness & Nutrition Calculators
Take control of your body composition, energy expenditure, and recovery with validated biometric algorithms. Private, client-side health tools with zero tracking.
Evidence-Based Biometrics & Energy Balance
Reaching your body composition and athletic goals requires treating metabolism as an exact energy balance. Whether your objective is cutting body fat, packing on lean muscle, or optimizing sleep recovery, physiological equations provide the scientific foundation for nutritional planning.
Our health calculators implement gold-standard peer-reviewed formulas: the Mifflin-St Jeor equation for Basal Metabolic Rate (BMR), the US Navy circumference method for body fat estimation, and ultradian 90-minute sleep cycle timing. Everything computes instantly in your browser without transmitting your personal biometric data.
Intermittent Fasting Calculator
Calculate your daily eating and fasting schedule for 16:8, 18:6, 20:4, and OMAD with a visual 24-hour timeline.
Pace Calculator
Calculate your running pace, target finish times, and distance splits with 1-tap 5K, 10K, half, and marathon presets.
Target Heart Rate Calculator
Calculate your 5 cardiovascular training zones and Zone 2 fat burn window using Karvonen and Tanaka formulas.
Calorie Deficit Calculator
Calculate your daily calorie target for fat loss, project weekly milestone dates, and set muscle-preserving macros.
One-Rep Max (1RM) Calculator
Calculate your true one-rep max using Epley and Brzycki formulas. Get exact percentage training loads and rep targets.
Macro Calculator
Calculate personalized daily grams of protein, carbs, and fat tailored to your body weight, activity level, and fitness goals.
TDEE (Total Daily Energy Expenditure) Calculator
Calculate your exact daily caloric maintenance needs based on BMR and physical activity multipliers for cutting, bulking, or maintenance.
BMR (Basal Metabolic Rate) Calculator
Calculate calories burned at complete rest using the scientifically validated Mifflin-St Jeor metabolic formula.
Body Fat Percentage Calculator
Estimate your body fat percentage and lean muscle mass using the official US Navy tape-measure circumference algorithm.
Ideal Body Weight (IBW) Calculator
Compare healthy target body weight ranges using Devine, Robinson, Miller, and Hamwi clinical equations.
BMI (Body Mass Index) Calculator
Calculate your Body Mass Index and identify healthy weight classifications for adults using standard World Health Organization criteria.
Sleep Cycle & Bedtime Calculator
Calculate optimal wake-up times and bedtimes based on 90-minute REM sleep cycles to wake up energized without sleep inertia.