Q
How much water should I really drink?
⚡ Quick answer
Around 2-3 litres daily for most adults. Urine should be pale yellow.
The "8 glasses a day" rule has no scientific basis but is roughly accurate for most people. The real answer depends on your size, activity, climate, and food.
Guidelines:
- Sedentary adult: 2-2.5 litres daily total fluids
- Active adult: 3-4 litres
- Hot climate or exercise: add 500-1000ml per hour of activity
- Pregnant women: 2.5-3 litres
- Breastfeeding women: 3-4 litres
Key insight: about 20% of fluid comes from food (especially fruits and vegetables). The rest comes from drinks — water, tea, coffee, soup, etc. All count.
The simplest test: urine should be pale yellow throughout the day. Dark yellow = drink more. Clear all day = drink less.
When to drink more:
- Hot weather
- During exercise
- Sick (especially fever, vomiting)
- High-protein diet
- Caffeine and alcohol consumption
When too much is dangerous: drinking 5+ litres in a few hours can cause hyponatremia (low sodium) — dangerous in athletes. Drink steadily through the day.
What does NOT count well: sugary drinks, alcohol (dehydrating), excessive caffeine.
Quality matters: filtered water is preferable for long-term health if your tap water has chlorine, fluoride concerns, or contaminants.
Read our full evidence-based guide on lifestyle for the complete picture.
View Full Guide →We write from peer-reviewed research and clinical guidance. These links let you read the underlying evidence yourself rather than taking our word for it.