Water Intake Calculator
Estimate your recommended daily water intake based on your bodyweight and exercise duration.
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Your result
2.8 L/day
Recommended water intake
AI explanation
Formula
Water (L/day) = (weight(kg) × 35 mL + exercise minutes / 30 × 350 mL) / 1000Worked example
70kg, 30 minutes of exercise
| Field | Value |
|---|---|
| Weight | 70 |
| Exercise duration | 30 |
| Recommended water intake | 2.8 |
Assumptions
- Uses a common baseline of 35 mL per kg bodyweight, plus roughly 350 mL for every 30 minutes of exercise to cover sweat losses.
- Does not account for climate, altitude, or individual sweat rate, all of which can meaningfully change actual needs.
- Informational only — not personalized medical advice, and not a substitute for thirst as a guide or for medical guidance if you have kidney or heart conditions that affect fluid intake.
Frequently asked questions
How much water should I drink per day?
A common baseline is about 35 mL per kg of bodyweight, plus extra for exercise or hot climates — for a 70kg person with light activity, that's roughly 2.5-3 liters per day.
Does this include water from food and other drinks?
No — this estimates total fluid intake from all sources combined, though in practice about 20% of fluid intake typically comes from food.
Should I drink more water in hot weather or at high altitude?
Yes — heat, humidity, and altitude all increase fluid losses through sweat and respiration, so needs can be meaningfully higher than this baseline estimate suggests.
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Related articles
Sources
- Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate — National Academies (Institute of Medicine). Effective 01-01-2005, reviewed 13-09-2026.
This calculator provides a general estimate only and does not constitute personalized medical advice. If you have a kidney, heart, or other condition that affects fluid balance, consult your doctor before changing your water intake.
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