Myth vs. Reality
The old advice of "drink 8 glasses of 8oz water a day" is a good starting point, but it's scientifically incomplete. It treats a 200lb athlete the same as a 100lb student.
Your actual range depends on your body mass (larger cells need more fluid) and your activity level (sweat loss).
Signs of Dehydration
Don't wait until you are thirsty. By then, you are already slightly dehydrated. The easiest test is checking your urine color:
- Pale Yellow (Straw): Perfect hydration.
- Dark Yellow: Drink water immediately.
- Amber / Orange: Severe dehydration.
Common Questions
Coffee & Tea?
Yes, they count! While caffeine is a mild diuretic, the water content in coffee still contributes to your daily total. Just don't rely on them exclusively.
Can I drink too much?
Yes. Hyponatremia (water intoxication) happens when you drink so much that you dilute your blood sodium levels. Stick to your target and listen to your body.
Tools & Data Verified by the EverydayCalculators Medical Research Team.
Last updated: December 2026.