Can babies drink water? How much, and when
Before 6 months, extra water can be harmful — milk covers hydration. From 6 months, small sips with meals are encouraged, with milk still the main drink.
This one runs against every adult instinct, especially in summer. Before 6 months, breast milk or formula covers hydration completely — they’re mostly water already, with the right electrolyte balance. Extra plain water does two harmful things to a small infant: it can dilute blood sodium (in serious cases leading to water intoxication and seizure risk), and it fills a tiny stomach with zero calories, displacing the milk they need to grow.
Heatwave protocol under 6 months: more milk feeds, not water. That’s the official guidance, not a compromise.
From 6 months, the picture flips: small sips of water with meals are encouraged — a few ounces across the day, ideally from an open or straw cup, which builds drinking skills most bottles don’t. Milk still remains the main drink through the first year.
Based on AAP and WHO guidance.
Frequently asked questions
Can a baby under 6 months drink water?
Not routinely. Before 6 months breast milk or formula covers hydration completely, and extra plain water can dilute blood sodium and fill a small stomach with no calories. In a heatwave, offer more milk feeds rather than water.
How much water can a 6-month-old have?
From 6 months, small sips with meals are encouraged — a few ounces across the day, ideally from an open or straw cup, which builds drinking skills. Milk stays the main drink through the first year.
Why can too much water be dangerous for a young baby?
In a small infant, too much plain water can dilute blood sodium — in serious cases leading to water intoxication and seizure risk — and it displaces the calorie-rich milk they need to grow.
Guidance, not medical advice — always supervise feeding and consult your pediatrician.