The general guideline for how much water you should drink daily based on your weight is to consume about half your body weight in ounces of water. For example, if you weigh 200 pounds, you should aim for roughly 100 ounces of water per day
How to Calculate Your Water Intake Based on Weight
- Take your weight in pounds.
- Divide that number by 2.
- Drink that many ounces of water daily.
For instance:
- 150 pounds → 75 ounces of water
- 180 pounds → 90 ounces of water
Adjustments for Activity and Other Factors
- If you exercise, add about 12 ounces of water for every 30 minutes of physical activity to compensate for water lost through sweat
- Hot or humid climates, pregnancy, breastfeeding, and other factors may increase your water needs, so you should drink more accordingly
- The standard "8 glasses a day" (64 ounces) is often insufficient for many people, especially those with higher body weight or active lifestyles
Alternative Metric (Metric System)
- Another recommendation is to drink about 28-35 ml per kg of body weight daily, which translates roughly to 2.1 to 2.5 liters for a 70 kg person
- A simpler formula is multiplying your weight in kilograms by 0.03 to get liters per day. For example, 70 kg × 0.03 = 2.1 liters
Summary Table
Weight (lbs)| Water Intake (oz)| Water Intake (liters)
---|---|---
100| 50| 1.5
150| 75| 2.2
200| 100| 3.0
250| 125| 3.7
Key Points
- Drink half your weight in ounces daily as a baseline.
- Add extra water for exercise (12 oz per 30 min).
- Adjust for climate, pregnancy, breastfeeding, and other factors.
- Monitor hydration by urine color (pale yellow is ideal).
- Pre-hydrate before activities and don’t wait until thirsty to drink
This weight-based approach provides a personalized hydration target that is more accurate than the generic "8 glasses a day" rule
