Daily Water Intake Calculator

The baseline is about 35 mL per kg of body weight for men and 30 mL per kg for women, then adjusted upward for activity level and hot climates.

Slightly. Older adults (50+) often have a somewhat reduced thirst response and slightly lower baseline fluid needs, so the calculator applies a small downward adjustment for ages over 50 and 65.

Yes. Pregnancy and breastfeeding both increase fluid needs (roughly 0.4-0.6 extra liters per day), and fever or illness with vomiting/diarrhea also raise fluid needs to replace losses.

Yes, in moderation — while caffeine has a mild diuretic effect, moderate coffee and tea consumption still contribute meaningfully to overall daily fluid intake.