Hydration Calculator (GTG Signature)

Estimate daily water intake using weight + activity + climate adjustments, with sweat-rate guidance, electrolyte awareness, caffeine/alcohol offsets, a simple hydration schedule, and sustainability insights. Educational tool — not medical advice.

Calculate your daily hydration

Enter your details and preferences. Results update instantly and save locally in your browser.

Important: If you have kidney/heart disease, uncontrolled diabetes, hyponatremia history, are pregnant, or take diuretics/NSAIDs, consult a qualified clinician before changing fluid/electrolyte intake. This tool provides estimates only.
Used for gentle risk flags (older adults often need reminders).
If 0, we use activity level only.
Higher altitude can increase fluid needs.
Coffee/energy drinks/strong tea.
Alcohol can increase dehydration risk.
High fiber often pairs best with more water.
Used to estimate “how many bottles.”
If set, overrides calculated total.
Daily target
Bottles/day
Electrolyte note
Hydration risk
Base need
Add-ons
Sustainability
Target breakdown:
Plan
Electrolytes
Schedule
Sustainability
Tips + Safety
Your plan
Enter weight + inputs to generate your hydration target.
Sweat-rate guidance
Based on training + heat/humidity (simple estimate).