Your Details
About This Calculator
A common rule of thumb is to drink half your body weight (in pounds) in fluid ounces per day. This calculator adjusts that baseline for activity level and climate.
Tips to hit your daily water goal
- Keep a reusable water bottle visible on your desk.
- Drink a glass of water when you wake up and before each meal.
- Fruits and vegetables count — they're 80–95% water.
- If your urine is pale yellow, you're well hydrated. Dark yellow means drink more.
Frequently asked questions
How does this water intake calculator work?
The water intake calculator starts from about half an ounce of water per pound of body weight, then adjusts for your activity level and climate to estimate a daily target in ounces, cups, liters, and milliliters.
How much water should I drink a day?
A common guideline is roughly half your body weight in pounds, taken as ounces, adjusted up for exercise and hot weather. It is an estimate — thirst is a reliable guide for most healthy adults.
Do coffee and food count toward water intake?
Yes. Food and other beverages contribute to your total fluid intake. This tool estimates total water needs, not only the plain water you have to drink.