How much water should you drink per day?
The calculator uses a weight-based formula: 35 mL of water per kilogram of body weight, adjusted for activity level. Sedentary adults use the base amount; active individuals add 20%; very active people add 40%. This is a general guideline — individual needs vary based on climate, health, diet, and other factors.
Activity level guide
Sedentary: desk job, little exercise. Active: light exercise 3–5 days/week or a physically demanding job. Very Active: intense exercise 6–7 days/week or an athletic lifestyle. Add extra water in hot weather or if you sweat heavily.
FAQ
Is the 8 glasses per day rule accurate?
The '8 × 8' rule (eight 8-oz glasses = ~2 liters) is a simple guideline but not based on individual weight. A weight-based calculation is more personalised. Actual needs also depend on climate, activity, diet, and health conditions.
Does coffee or tea count toward water intake?
Mild caffeinated drinks like coffee and tea do contribute to your fluid intake, though their mild diuretic effect means they hydrate slightly less efficiently than plain water. Strongly caffeinated or alcoholic drinks do not count.