Water Intake Calculator
Calculate your recommended daily water intake based on your body weight, activity level, and climate. Get targets in litres and glasses.
Your Profile
Daily Water Target
2.8 L
12 glasses (250 ml each)
Breakdown
How It Works
The baseline recommendation is 35 ml of water per kg of body weight per day. This is adjusted upward for physical activity (you lose water through sweat), hot or humid climates, pregnancy, and breastfeeding. The result is split into glasses (250 ml each) for easy tracking throughout the day.
Water Intake Formula
Base: 35 ml × body weight (kg). Activity bonus: +350–700 ml. Climate bonus: +350 ml (hot/humid). Pregnancy: +300 ml. Breastfeeding: +700 ml.
Hydration Signs
- Well hydrated
- Pale yellow urine, no headache, good energy and concentration
- Mild dehydration
- Dark yellow urine, slight headache, reduced focus or dry mouth
- Dehydrated
- Amber urine, headache, fatigue, dizziness — drink water immediately
- Overhydrated
- Clear urine very frequently — excess water dilutes sodium; rare but possible
Frequently Asked Questions
Is the 8 glasses a day rule accurate?
The '8×8' rule (eight 8-oz glasses = ~2 litres) is a rough guideline, not science. Your actual need depends on your weight, activity, climate, and diet. Heavier and more active people need more. Food also contributes about 20% of daily water intake.
How do I know if I'm drinking enough water?
The simplest check: urine color. Pale yellow means well-hydrated. Dark yellow or amber means you need more water. Clear urine may indicate overhydration. Other signs of dehydration: headache, fatigue, dry mouth, and reduced concentration.
Does tea and coffee count toward daily water intake?
Yes — tea, coffee, milk, and juices all contribute to hydration. The mild diuretic effect of caffeine is not enough to cancel out the fluid intake. Plain water is still the best source, but other beverages count.
Should I drink more water when exercising?
Yes. Drink 500 ml 2 hours before exercise, 150–250 ml every 15–20 minutes during exercise, and 500–750 ml for every 0.5 kg lost during the workout. For sessions over 60 minutes, consider an electrolyte drink.