Estimate how much water you should drink each day based on your weight and activity level.
This calculator estimates a general daily water intake target based on your body weight and activity level, using a common baseline of 35 ml of water per kilogram of body weight, plus an allowance for exercise.
Base intake (ml) = weight (kg) × 35, then add extra ml based on activity level (0 for sedentary, 350 ml for lightly active, 700 ml for very active). The result is converted to liters and approximate 8 oz cups.
A person weighing 70 kg who is lightly active needs about 70 × 35 = 2,450 ml, plus 350 ml for activity = 2,800 ml (2.8 liters), or roughly 12 cups per day. Enter 70 kg and "Lightly active" above to confirm.
This is a general estimate. Actual needs vary with climate, health conditions, and diet. Consult a healthcare provider for personalized hydration guidance, especially if you have a medical condition.
Common formulas base it on body weight, adjusted for activity level and climate.
It's a popular general guideline; actual needs vary by individual factors.
Most fluids and water-rich foods contribute, though caffeine/alcohol have mild diuretic effects.