Health
Daily Water Intake Calculator
Your daily hydration target based on body weight and activity level.
How much water do you need?
The "8 glasses a day" rule is an approximation. Your real needs depend on body weight and activity level.
Base oz = Body weight (lbs) ÷ 2
Add 12 oz per 30 min of exercise
Signs of dehydration
- Dark yellow urine (pale yellow = well hydrated)
- Persistent thirst or dry mouth
- Headaches and difficulty concentrating
- Fatigue and reduced physical performance
Tips for drinking more
- Keep a water bottle at your desk at all times
- Drink a full glass before each meal
- Set hourly phone reminders
Frequently asked questions
Does coffee count toward daily water intake?▾
Yes. Despite mild diuretic effects, caffeinated drinks still contribute net hydration.
Should I drink more water when exercising?▾
Yes. Add 12 oz for every 30 minutes of moderate exercise. In heat, increase further and consider electrolytes for sessions over 60 minutes.
✓ Math logic verified against primary sources
→ See our verification process