Free Tool
Water Intake Calculator
Find out how much water you should drink each day, personalised to your body weight, activity level and climate.
Your hydration target appears here
Enter your weight and activity, and we'll calculate how much water you should drink each day.
Recommended daily water
Spread evenly across the day — don't drink it all at once.
How your target breaks down
This is a general estimate, not medical advice. Individual needs vary — those who are pregnant, breastfeeding, or have kidney or heart conditions should follow their doctor's guidance.
Hydrate smarter
Support hydration and recovery with our electrolyte and greens range.
How much water do you really need?
The old "8 glasses a day" rule is a useful starting point, but your real needs depend on your body weight, activity level and environment. This calculator estimates your daily fluid target from roughly 33ml of water per kilogram of body weight, then adds extra for exercise and hot conditions.
Remember that food (especially fruit and vegetables) and other drinks also count toward your total fluid intake — so you don't need to hit this entirely through plain water.
Tips to stay hydrated
- ✓ Start your day with a glass of water before coffee.
- ✓ Keep a reusable bottle visible on your desk.
- ✓ Drink to thirst, and a little extra around workouts.
- ✓ Check your urine — pale straw colour means well hydrated.
- ✓ Electrolytes help retention during long or sweaty sessions.
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