Water Intake Calculator

Calculate how much water you should drink daily based on your body weight, activity level, and climate. Get your recommendation in ounces, cups, and liters — plus how that breaks down by the glass and bottle.

Daily Hydration Calculator

Daily Water Intake Formula

Base intake = body weight (lbs) × 0.5 oz (or weight kg × 35 mL) Activity add = extra oz based on exercise level Climate add = extra oz for heat/humidity Total = Base + Activity + Climate

Hydration Guidelines

SourceDaily Recommendation
Institute of Medicine (men)~125 oz / 3.7 liters
Institute of Medicine (women)~91 oz / 2.7 liters
"8×8" rule (popular guideline)64 oz / ~1.9 liters
Weight-based rule0.5 oz per pound of body weight

Frequently Asked Questions

Does coffee and tea count toward water intake?+
Yes. Despite mild diuretic effects, caffeinated beverages like coffee and tea still contribute to daily hydration. Most of the fluid in coffee and tea is absorbed by the body. Beverages other than alcohol can be counted toward your fluid intake.
What are signs of dehydration?+
Early signs include dark-yellow urine, thirst, dry mouth, and fatigue. Moderate dehydration can cause headaches, dizziness, and reduced performance. Your urine should be pale yellow to clear when properly hydrated.

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