Daily Water Intake Guide: How Much Water Do You Really Need?

How Much Water Do You Need?

The common "8 glasses a day" advice is a rough guide. Your actual needs depend on body weight, activity level, climate, and diet. A better formula: 30-35ml per kg of body weight per day. For a 70kg person, that's 2.1-2.45 litres.

Factors That Increase Need

Exercise: Add 500-1,000ml per hour of moderate to intense exercise. Hot weather: Increase by 500-750ml on hot days. Altitude: Higher altitudes increase fluid loss. Pregnancy/breastfeeding: Add 300ml (pregnancy) or 700ml (breastfeeding). Illness: Fever, vomiting, and diarrhoea all increase fluid needs significantly.

Signs of Dehydration

The simplest indicator is urine colour — aim for pale straw colour. Other signs include: thirst (you're already mildly dehydrated by the time you feel thirsty), headaches, fatigue, dizziness, dry mouth, decreased concentration, and dark urine.

Does It Have to Be Water?

No. All fluids count including tea, coffee, milk, and juice. Even food contributes — fruits and vegetables are 80-95% water. Soups, yoghurt, and other water-rich foods count too. However, sugary drinks add unnecessary calories.

Practical Tips

Carry a reusable water bottle and refill it regularly. Drink a glass with every meal. Set reminders on your phone if you forget. Flavour water with lemon, cucumber, or mint if you find plain water boring. Drink before you feel thirsty — thirst is a late indicator of dehydration.