Most people guess their hydration. They drink when they’re thirstyor follow generic advicethat ignores what actually matters. How much you sweat. This spreadsheet showshow much fluid and electrolytes you lose per houracross different activitiesbased on real-world sweat data. Gym.Running.Combat sports.Labour work.Endurance sessions. You enter your bodyweight once. And every sweat-loss numberautomatically adjusts to your size. Nothing complex. Just 1 inputNo tracking apps.No overthinking. Just a clear reference forhow hard your body is bleeding fluid and saltduring real work. What It Does Hourly sweat-loss estimates by activity Automatically scales to bodyweight Metric-based and easy to read Works as a standalone reference or alongside any hydration strategy No setup beyond entering your weight This isn’t a “drink X litres per day” tool. It’s a rate-based reality check. Why This Matters Most hydration mistakes come from not knowing your loss rate. That leads to: chronic underhydration low sodium intake fatigue and headaches cramps poor performance brain fog during long sessions If you don’t know what you’re losing,you can’t replace it properly. Who This Is For Anyone who: trains hard sweats heavily works physical jobs lives in hot environments wants fewer guesses and better outcomes This index doesn’t replace awareness.It sharpens it. Download It Free Instant access.No paywall. Just a clear frameworkfor understanding your sweat. Disclaimer This tool provides estimates, not medical advice. Sweat rates vary based on genetics, heat acclimation, clothing, airflow, and individual physiology. Use real-world feedback and common sense. If you have a medical condition affecting hydration or electrolytes, consult a qualified professional.
