How Much Water Should You Drink?
While the old "8 glasses a day" rule is a good start, your actual hydration needs depend on your body weight and activity level. A larger person requires more water to function than a smaller person, and exercise rapidly depletes hydration levels.
The Math Behind Hydration
This calculator uses the standard health recommendation formula:
- Baseline: You should drink roughly 50% to 67% of your body weight (lbs) in ounces of water per day.
- Activity Modifier: For every 30 minutes of moderate exercise, you should add roughly 12 ounces of water.
Why Hydration Matters
Proper water intake helps regulate body temperature, keeps joints lubricated, prevents infections, and delivers nutrients to cells. Being well-hydrated also improves sleep quality, cognition, and mood.