Use our science-backed free calculators to evaluate your fitness stats, track hydration, time fasting windows, and calculate sleep patterns. Or sign up to unlock automated meal planning.
Calculate your Body Mass Index, daily calorie needs, and optimal macronutrient breakdown based on your goals.
Find your Total Daily Energy Expenditure based on activity level, age, gender, and body metrics.
Estimate your body fat percentage using the US Navy method with waist, neck, and hip measurements.
Practice Box Breathing, 4-7-8, and Coherent breathing with smooth visual counters and audio chimes to calm anxiety.
Calculate custom fluid target requirements based on weight, exercise, climate, and log daily glasses to fill the wave gauge.
Track fast intervals (16:8, 18:6, custom), review active biological stages, and follow metabolic cellular repairs.
Plan bedtimes or wake cycles centered on 90-minute sleep metrics to avoid grogginess and wake up fully energized.
Find your exercise aerobic and fat-burn conditioning zones, and estimate VO2 Max using submaximal walk test data.
Have questions about how our tools work? Here is a breakdown of our privacy safeguards, calculations, and offline capabilities.
Yes, completely free. You don’t need to register or sign up to check your metrics, track your water, or time your fasts.
All logs (like daily water intake and active fasting timers) are saved locally in your own browser's storage. We do not store or see any of your personal metrics.
We use standard, science-backed formulas (such as the US Navy body fat calculations and Karvonen heart rate zones). They provide excellent estimates, but are for educational use and shouldn't replace professional medical advice.
Because sleep naturally runs in 90-minute REM cycles. Waking up at the end of a cycle (when sleep is lightest) prevents morning grogginess and leaves you feeling refreshed.
Yes! Because our site works as a Progressive Web App (PWA), these calculators will remain fully functional even when you are offline or have weak signal at the gym.