Water Intake Calculator
Estimate your daily water intake based on your weight, activity, and climate.
How to Estimate Your Water Intake
- Enter your weight and choose kilograms or pounds.
- Enter how many minutes you exercise on a typical day.
- Select your climate — hot or humid conditions increase fluid loss.
- Your estimated daily water intake updates instantly, in liters, milliliters, cups, and ounces.
Frequently Asked Questions
What formula does this water intake calculator use?
It starts from a commonly cited baseline of about 33 mL of water per kilogram of body weight per day, then adds roughly 350 mL for each 30 minutes of exercise, and applies a small upward adjustment for hot climates. It's a widely used general guideline, not a personalized medical calculation.
Does this count water from food and other drinks?
No — this estimates total plain water intake specifically. In practice, food and other beverages also contribute meaningfully to daily hydration, so your total fluid needs from all sources may already be partly met before you account for water alone.
Is this medical advice?
No. This is a general wellness estimate, not medical guidance. Actual hydration needs vary by individual health conditions, medications, pregnancy, and climate — consult a doctor for advice specific to you, especially if you have a kidney, heart, or other condition affected by fluid intake.
Is my data sent anywhere?
No — the estimate is calculated entirely in your browser using JavaScript, so nothing you enter is ever sent to a server.