Water intake calculator.

A common baseline is one half to two thirds of an ounce of water per pound of body weight per day, plus roughly 12 ounces for every 30 minutes of exercise. Food contributes fluid too, so the target includes all sources, not only what you pour from a bottle.

Thirst becomes a less reliable signal with age and with appetite-suppressing medication, so having an actual number to aim for beats guessing.

GLP-1 medications slow how quickly your stomach empties and quiet the appetite signals that normally remind you to eat and drink. Members on these protocols often drink noticeably less without realizing it, and mild dehydration can amplify side effects like nausea, fatigue, and constipation.

If you are on a clinician-guided protocol, steady hydration through the day is one of the simplest things you can do to feel better on it. Your care team can help if you struggle to keep fluids up.