Hydration calculator
GLP-1 Water Intake Calculator
Build a reasonable fluid target for today, with room for movement and heat—without turning hydration into a contest.
Estimate today's fluid target
2.8 liters / day
This includes water and other fluids, not just plain water. Sip across the day; more is not always better, especially with kidney or heart conditions.
A baseline, not a mandate
The calculator starts at 30 milliliters per kilogram of body weight, a practical clinical planning value, then adds modest buffers for exercise and warm conditions. Food moisture and other beverages count. Needs vary with sweat rate, altitude, illness, pregnancy, kidney function, and other medicines.
Water first, electrolytes when useful
Most routine hydration can start with water and regular food. If you are replacing substantial sweat or gastrointestinal losses, compare sodium and sugar—not just flavor—in our electrolyte guide. A 1,000 mg sodium packet is a materially different product from a 55 mg sodium powder.
Use symptoms as a safety signal
Persistent gastrointestinal symptoms are a reason to contact your prescriber. The FDA label specifically connects dehydration from nausea, vomiting, or diarrhea with reports of acute kidney injury. Do not use more fluid or electrolytes to delay appropriate care.
Straight answers
Frequently asked questions
Do GLP-1 medicines cause dehydration?
The medicine itself does not mean everyone needs extra fluid, but nausea, vomiting, diarrhea, reduced intake, and lower thirst can contribute to fluid loss. Current Wegovy labeling warns about kidney injury from volume depletion associated with gastrointestinal reactions.
Do I need an electrolyte powder every day?
Not automatically. Plain water and food are enough for many people. Electrolytes may be useful after meaningful sweat or gastrointestinal losses, but high-sodium products are not a universal daily wellness need. Ask a clinician if you have high blood pressure, kidney disease, heart disease, or take medicines that affect fluid or electrolytes.
Does coffee count toward fluid intake?
Most nonalcoholic beverages contribute to total fluid intake. Water is still a simple default, and calorie- or sugar-containing drinks should be considered in the context of your full nutrition plan.
When should I contact my prescriber?
Contact your clinician for persistent vomiting or diarrhea, inability to keep liquids down, very low urine output, fainting, confusion, severe weakness, or other concerning symptoms. These are not situations to solve with an online calculator.
Sources and method
Formula choices and health context were checked against the sources below in July 2026. Estimates are rounded so they stay practical.