Water Intake Calculator
Estimate daily water intake using a simple guideline based on body weight and activity. Results are a general reference, not medical advice.
Result will appear here.
Informational estimate only. Your needs may vary based on climate, diet, health conditions, and exercise.
Privacy: calculations run locally in your browser. No inputs are stored or sent to a server.
How it works
This tool uses a simple hydration guideline based on body weight, then applies a small adjustment for higher activity. The base estimate is approximately 35 ml per kg of body weight per day (a commonly used rule-of-thumb).
- Base estimate: weight(kg) × 35 ml
- Activity adjustment: adds a small amount for moderate/high activity
- Cups: shown as an approximation using 1 cup ≈ 240 ml
This is not a medical recommendation. If you have kidney/heart conditions, are pregnant, or have specific medical needs, consult a professional.
Examples
- 70 kg, low activity → about 2.45 L (≈ 10 cups)
- 70 kg, moderate activity → higher estimate with adjustment
- 150 lb, low activity → roughly 2.4 L (approx.)
FAQ
- How much water should I drink per day? Many people use weight-based guidelines, but needs vary widely.
- Is this a medical recommendation? No. It’s an informational estimate based on a rule-of-thumb.
- Does coffee/tea count as water? Fluids contribute, but individual tolerance to caffeine varies.
- Why show cups? It helps quick planning. Cups are approximate (1 cup ≈ 240 ml).
- Is my data stored? No. The calculation runs locally in your browser.