Hydration

Daily Water Intake Calculator

Find out exactly how much water you should drink each day based on your weight, activity level, and climate.


Litres per day
fl oz / day
cups / day
500ml bottles
ml / hour (waking)

Hydration Tips

  • Drink a large glass of water first thing in the morning to rehydrate after sleep.
  • Drink 500ml of water 30–60 minutes before exercise, then 200ml every 20 minutes during.
  • Dark yellow urine means you need to drink more. Pale yellow is ideal.
  • Coffee and tea count toward your daily intake — the diuretic effect is minimal at moderate consumption.
  • Add 350–700ml for every hour of intense exercise in the heat.

How daily water needs are calculated

The base formula uses 35ml per kg of bodyweight (or about 0.5 oz per lb). This is then adjusted upward for higher activity levels and hot/humid climates which increase sweat losses. Individual needs vary — these are science-based starting points.

Water vs other beverages

Plain water is best, but milk, juice, herbal teas, and even coffee and caffeinated tea contribute to your daily fluid intake. Alcohol is dehydrating and should not be counted. Foods like fruits, vegetables, and soups also contribute significantly — roughly 20% of daily water intake comes from food for most people.