When Can Babies Have Water? (What Pediatricians Recommend)

Updated on October 24, 2025 • U.S. parents’ guide

Why No Water Before 6 Months?

Before 6 months, babies’ nutrition and hydration needs are fully met by breast milk or properly prepared infant formula. Extra water can fill tiny stomachs without nutrients and dilute electrolytes (especially sodium), which—if excessive—may lead to seizures. :contentReference[oaicite:3]{index=3}

• Don’t dilute formula. Always mix exactly as directed. Over-dilution can be dangerous. :contentReference[oaicite:4]{index=4}
• Illness & hot weather: Even then, infants under 6 months generally need breast milk or formula; use oral rehydration solution (ORS) only when advised, not plain water. :contentReference[oaicite:5]{index=5}

When to Start & How Much Water for Babies

Around the time you begin complementary solids—typically near 6 months—you can introduce small amounts of water. It’s mainly for practice with cups and to complement solid meals. :contentReference[oaicite:6]{index=6}

• 6–12 months: Offer about 4–8 oz total per day (0.5–1 cup) in short sips; breast milk or formula remains primary. :contentReference[oaicite:7]{index=7}
• How to serve: Use an open cup, straw cup, or sippy to build drinking skills. :contentReference[oaicite:8]{index=8}
• 12+ months: Water becomes the go-to drink alongside plain milk; avoid sugary beverages. :contentReference[oaicite:9]{index=9}

What Kind of Water Is Best?

For most U.S. families, tap water is fine. If your community water is fluoridated, tiny sips help protect teeth as your child grows. Always follow your pediatrician’s guidance if you use well water or have local advisories. :contentReference[oaicite:10]{index=10}

• Fluoride: Community fluoridation supports cavity prevention; your pediatrician/dentist can advise for your area. :contentReference[oaicite:11]{index=11}
• For formula preparation: Use safe water as directed by your pediatrician/brand instructions. (Some families are advised to boil/sterilize depending on local safety and age.)
• Bottled water: Check mineral/sodium levels if using regularly; when in doubt, ask your clinician.

Safety First: Water Intoxication & Red Flags

Giving too much water—especially to infants under 6 months—can cause hyponatremia (low blood sodium), which may lead to lethargy, vomiting, or seizures. Seek care immediately if you suspect this. :contentReference[oaicite:12]{index=12}

• Never stretch formula with extra water. :contentReference[oaicite:13]{index=13}
• If your baby has vomiting/diarrhea, ask your pediatrician about ORS instead of plain water. :contentReference[oaicite:14]{index=14}

Practical Tips for Parents

• Offer water with solids around 6 months; keep portions small and unpressured. :contentReference[oaicite:15]{index=15}
• Model sipping from your own cup—babies copy you.
• Expect tiny intakes at first. Skill-building is the goal, not volume.
• Ask your pediatrician sooner if your baby was premature, has health conditions, or you use well water.

FAQs

Can a 3-month-old have water?

• No. Under 6 months, stick to breast milk or formula unless your clinician advises otherwise. :contentReference[oaicite:16]{index=16}

How much water for a 6–12-month-old?

• About 4–8 oz/day total (0.5–1 cup) in small sips; keep breast milk or formula as the main drink. :contentReference[oaicite:17]{index=17}

When should we start a cup?

• Offer an open, straw, or sippy cup when solids begin—usually around 6 months. :contentReference[oaicite:18]{index=18}

Is sparkling water okay for babies?

• Not recommended. Bubbles can cause gas/discomfort, and flavored varieties may be acidic. Stick to plain water in small amounts after 6 months; milk/water are main drinks after 12 months. :contentReference[oaicite:19]{index=19}

References & Further Reading

• AAP HealthyChildren — Recommended Drinks 0–5 (water at ~6 months; 4–8 oz/day). :contentReference[oaicite:20]{index=20}
• AAP HealthyChildren — Choose Water for Healthy Hydration. :contentReference[oaicite:21]{index=21}
• CDC — Hyponatremic Seizures Among Infants (water intoxication risk). :contentReference[oaicite:22]{index=22}
• CDC — Foods & Drinks for 6–24 Months. :contentReference[oaicite:23]{index=23}
• WHO — Complementary Feeding Overview (~6 months). :contentReference[oaicite:24]{index=24}