Calculate how much water you should drink each day based on body weight, activity level, exercise time, climate, and special conditions like pregnancy or breastfeeding. Backed by Mayo Clinic, EFSA, IOM & sports nutrition guidelines (updated 2026).
Daily fluid needs vary widely. According to the Mayo Clinic, U.S. National Academies (IOM), and EFSA:
~20% comes from food (fruits, vegetables, soups), so aim for ~80% from drinks. This calculator personalizes the recommendation using:
These align with Mayo Clinic, American College of Sports Medicine, and recent hydration studies (2023–2025).
Pro tips:
| Good Hydration | Dehydration Warning |
|---|---|
| Pale yellow / straw-colored urine | Dark yellow / amber urine |
| Urinating every 2–4 hours | Infrequent urination or small amounts |
| No thirst / dry mouth | Persistent thirst, dry lips/tongue |
| Good energy, focus, skin elasticity | Fatigue, headache, dizziness, dry skin |
Severe signs (confusion, rapid heartbeat) → seek medical help immediately.
No — the fluid in coffee/tea counts toward your total. Caffeine has only a mild diuretic effect in regular consumers (Mayo Clinic, 2025).
Pregnant: +300 ml/day (~total 3–3.5 L). Breastfeeding: +700–1,000 ml/day (~3.5–4 L) to support milk production (IOM & Mayo Clinic).
No — it’s a rough average. A 90 kg active person in hot weather may need 4–6 L, while a small sedentary person may need ~2 L (personalized calculators are better).
Usually not for normal daily intake. But for exercise >60–90 min, heavy sweating, or hot climates — add sodium/potassium (sports drink, pinch of salt, banana) to avoid hyponatremia.
Yes — overhydration (hyponatremia) is rare but possible if you drink >1 L/hour without electrolytes. Listen to thirst and urine color.