Set your daily goal
Use body weight, activity, and weather to generate a practical daily water target.
Today's hydration progress
Your target, remaining amount, and running intake log stay in sync as you add drinks.
Progress bar
Quick add water
Add a custom amount
No drinks logged yet. Use a quick add button or enter a custom amount.
How it works
The target is intentionally simple and transparent so you can adjust it without guessing what the calculator is doing.
Baseline target
The page starts with a baseline of half your body weight in fluid ounces per day. If you enter kilograms, the calculator converts to pounds first, then applies the same rule.
Activity and heat adjustment
It adds 12 fluid ounces for every 30 active minutes, plus a small climate bump for mild or hot conditions. Longer waking hours also nudge the target upward.
Progress and pacing
Your pace guide divides the total target by selected waking hours. Remaining water never drops below zero on screen, and progress caps at 100% so the bar stays stable.
Hydration needs vary with medications, pregnancy, illness, sweating rate, altitude, and medical conditions. This page is a planning aid, not medical advice.