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Health

Daily Water Intake Calculator

Last updated: July 11, 2026

Calculate how much water you should drink daily based on your weight, activity level, and climate. Get personalized hydration recommendations in ml, liters, cups, and ounces.

How to Use This Calculator

  1. Enter your Weight and select the unit (kg or lb).
  2. Select your Activity Level (how often you exercise).
  3. Select your Climate (hotter climates increase hydration needs).
  4. Click Calculate Water Intake to see your personalized recommendation in multiple units.

Formula

Adjusted Intake = Weight (kg) × 33 ml × Activity Multiplier × Climate Multiplier

General Guidelines: Sedentary adults need approximately 30 ml per kg of body weight, moderately active people 35–40 ml/kg, and those in very hot climates or with intense exercise may need 40–50 ml/kg.

Examples

70 kg, light exercise, temperate climate:

70 × 33 × 1.2 = 2,772 ml ≈ 11.6 cups = 2.77 L

55 kg, sedentary, cold climate:

55 × 33 × 0.9 = 1,633 ml ≈ 6.8 cups = 1.63 L

85 kg, very active, hot climate:

85 × 33 × 1.6 × 1.2 = 5,386 ml ≈ 22.4 cups = 5.39 L

Frequently Asked Questions

Is 8 glasses of water a day enough?

The "8 glasses" rule is a general guideline. Actual needs vary based on weight, activity, climate, and individual factors.

Does coffee or tea count toward my intake?

Yes, in moderation. Caffeinated beverages contribute to hydration but may have a mild diuretic effect.

Can I drink too much water?

Yes. Excessive water intake can lead to hyponatremia (low sodium). Stick to recommended amounts and listen to your body.

How do I know if I'm dehydrated?

Common signs include dark urine, dry mouth, fatigue, headache, dizziness, and decreased urine output.

Disclaimer: This calculator provides general hydration guidelines. Individual water needs vary based on health conditions, medications, pregnancy, and other factors. Consult a healthcare provider for personalized recommendations.