Daily Water Intake Calculator
Calculate how much water you should drink daily based on your weight and activity level.
How Much Water Do You Need?
The general guideline is to drink about 30-35 ml of water per kg of body weight per day. For a 70 kg person, that is approximately 2.1-2.5 liters. However, your actual needs depend on activity level, climate, diet, and health conditions.
The popular advice of 8 glasses (about 2 liters) per day is a reasonable baseline for most adults, but individual needs vary significantly.
Signs of Dehydration
Watch for these common signs that you need more water:
- Dark urine: Aim for pale yellow — dark yellow indicates dehydration
- Thirst: By the time you feel thirsty, you may already be mildly dehydrated
- Fatigue: Even mild dehydration (1-2%) can impair energy and mood
- Headaches: Dehydration is a common trigger for headaches
- Dry mouth and skin
During exercise, drink 150-250 ml every 15-20 minutes. In hot weather, increase your intake by 500-1000 ml per day.
Frequently Asked Questions
Can I drink too much water?
Yes, drinking excessive amounts of water can lead to hyponatremia (low sodium levels), though this is rare. Most people are more at risk of drinking too little than too much.
Do coffee and tea count toward water intake?
Yes, caffeinated beverages do contribute to your daily fluid intake. While caffeine has a mild diuretic effect, the water content more than offsets it.
Should I drink more water when exercising?
Yes. Drink 500 ml 2 hours before exercise, 150-250 ml every 15-20 minutes during, and 500-750 ml after for every 0.5 kg of weight lost during exercise.