how much water a day should you drink
Last updated September 6, 2026.
Most healthy adults do well with roughly 6 to 8 cups of plain water a day, since food and other drinks supply the rest of the fluid you need. Total fluid targets often quoted are about 11.5 cups (2.7 liters) a day for women and about 15.5 cups (3.7 liters) for men, but that total includes water from food, coffee, tea, milk, and soup, so what you actually drink is less. Your needs go up with hot weather, exercise, fever, vomiting, diarrhea, pregnancy, and breastfeeding. The simplest check is your body: drink when you are thirsty, and aim for urine that is pale yellow rather than dark. Spreading water across the day works better than drinking a large amount at once. If you have heart failure, kidney disease, or take a diuretic, your clinician may set a specific fluid limit that overrides these general numbers.
What to do
- Follow thirst first: For healthy adults, drinking when you feel thirsty covers most days without counting cups.
- Check your urine: Pale yellow means you are on track, while dark yellow or a low volume means drink more.
- Add for heat and exercise: Drink extra before, during, and after workouts or time outdoors in hot weather.
- Replace losses when sick: With fever, vomiting, or diarrhea, take small sips often and use an oral rehydration drink if you cannot keep fluids down.
- Choose water by default: Water and unsweetened drinks hydrate you without added sugar, and coffee and tea still count toward your total.
- Ask about fluid limits: If you have heart failure, kidney disease, liver disease, or take a diuretic, confirm your target with a clinician instead of increasing on your own.
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