Find how much water you should drink daily based on your body weight, activity level, and climate. See your target in liters, milliliters, glasses, and fluid ounces.
| Weight | Liters | ml | Glasses | Oz |
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Water is the most essential nutrient your body needs. It regulates temperature, transports nutrients, removes waste, lubricates joints, and supports every cellular process in your body. Even mild dehydration (1-2% body weight loss in fluid) impairs cognitive function, physical performance, and mood. This guide shows you how much water you actually need and how to stay properly hydrated.
Scenario 1: Office Worker in Temperate Climate. Sarah, 60 kg, sedentary, drinks 2 cups of coffee daily. Base: 2,100 ml. Exercise: 0. Climate: 0. Caffeine offset: 250 ml. Total: 2,350 ml (9 glasses). She keeps a 750ml bottle at her desk and refills it 3 times. Use our Calorie Deficit Calculator — drinking 500ml before meals reduces calorie intake.
Scenario 2: Active Person in Hot Climate. Marcus, 85 kg, runs 45 minutes daily in Trinidad (hot/humid). Base: 2,975 ml. Exercise: 750 ml. Climate: 500 ml. Total: 4,225 ml (17 glasses). Nearly double a sedentary person. He adds electrolytes during runs. Use our Calories Burned Calculator to pair hydration with exercise.
Scenario 3: Weight Loss Dieter. Priya, 75 kg, moderately active, on a calorie deficit. Base: 2,625 ml. Exercise: 500 ml. Total: 3,125 ml (13 glasses). She drinks 500 ml before every meal (3x daily = 1,500 ml toward target) which also reduces appetite. Research shows pre-meal water reduces intake by 75-90 calories per meal.
Scenario 4: Heavy Coffee Drinker. David drinks 5 cups of coffee daily. 70 kg, lightly active. Base: 2,450 ml. Exercise: 500 ml. Caffeine: 625 ml. Total: 3,575 ml (14 glasses). His caffeine offset alone adds 625 ml. Without compensating, he would be chronically mildly dehydrated despite drinking fluids all day. Use our TDEE Calculator to pair nutrition with hydration.
💡 Key insight: Most people are mildly dehydrated without knowing it. A 2% drop in hydration (1.4 kg fluid loss for a 70 kg person) causes measurable declines in concentration, mood, and physical performance. The fix is simple: drink before you feel thirsty, carry a water bottle, and check your urine color (pale yellow = hydrated).
| Clear urine | Overhydrated |
| Pale yellow | Well hydrated |
| Yellow | Drink more |
| Dark yellow | Dehydrated |
| Amber/brown | Seek fluids now |