Why use this calculator
Proper hydration is essential for energy, cognitive function, digestion, and overall health. Your needs vary based on weight, activity, and climate.
How to use it
Enter your weight, select your activity level and climate. The calculator estimates your daily water needs.
The formula
Base: half your body weight in ounces. Adjusted for activity (1.0-1.5x) and climate (0.9-1.2x).
Worked examples
170 lbs, moderate exercise, temperate climate
About 102 oz (3.0 L) per day
When people use it
- Daily hydration planning
- Athletic training
- Health optimization
Tips
- Don't wait until you're thirsty — that means you're already dehydrated
- Foods like fruits and vegetables count toward water intake
- Urine color is a good hydration indicator — aim for pale yellow
Questions people ask
- Can I drink too much water?
- Yes, though rare. Hyponatremia (water intoxication) can occur from extreme overconsumption. For most people, following thirst cues and this calculator's guidance is safe.