You can start offering your baby small sips of water at around 6 months of age, right when solid foods typically enter the picture. Before that point, breast milk or formula provides all the hydration a baby needs. The goal at 6 months isn’t to make water a major part of your baby’s diet. It’s to let them practice drinking and get familiar with the taste, while keeping intake between 4 and 8 ounces per day (about half a cup to one cup).
Why 6 Months Is the Starting Point
Before 6 months, a baby’s kidneys are too immature to process extra water safely. Young infants also have a powerful hunger drive that can lead them to fill up on water instead of calorie-rich milk, which slows growth. When a baby under 6 months takes in too much plain water, sodium levels in the blood can drop rapidly, a condition called water intoxication. Symptoms appear when sodium falls low enough to disrupt normal brain function, and in documented cases, this has caused seizures in young infants. The risk drops significantly once kidneys mature and babies start eating solid food, which is why 6 months is the widely recommended threshold.
Breast milk and formula are already mostly water. Even in hot weather, a baby younger than 6 months who is feeding well does not need supplemental water.
How Much Water to Offer
Between 6 and 12 months, aim for 4 to 8 ounces of water spread across the day. That’s a small amount on purpose. At this age, breast milk or formula is still the primary source of nutrition and hydration, and water should complement meals rather than replace them. Offering a few sips with each solid food meal is a practical way to stay within that range without overthinking exact measurements.
A baby who drinks too much water may nurse less or take less formula, which means fewer calories and nutrients during a critical growth period. Think of water as a side dish, not a main course. If your baby seems uninterested in water at first, that’s completely normal. They’re still getting plenty of fluids from milk.
Choosing a Cup
Skip the bottle for water. This is a good opportunity to introduce a cup, which supports oral development and helps your baby start building a new skill. You have three main options: an open cup, a straw cup, or a combination of both.
Open Cups
Open cups are great for oral motor development because they teach a baby to control the flow of liquid with their lip. The tradeoff is mess. Most 6-month-olds can’t hold or tilt an open cup on their own, so you’ll be holding it for them and pouring just a couple of sips at a time. Many parents find that their baby actually enjoys drinking from an open cup, even at this young age, especially babies who have resisted bottles. Expect spills. Pour small amounts so a tipped cup doesn’t become a flood.
Straw Cups
Straw cups are the more practical everyday choice because they spill less and work at any angle, especially weighted straw versions where the straw bends toward the water no matter how the baby holds it. Straws are also better for oral development than traditional sippy cups with hard spouts, which encourage a sucking pattern similar to a bottle rather than the more mature drinking motion you want your baby to learn.
Many parents use both types: a straw cup for meals during the day when convenience matters, and an open cup at dinner or when they have more patience for cleanup. Trying both early lets your baby get comfortable with different drinking methods, and there’s no single “right” choice.
Practical Tips for the First Few Weeks
Start by offering water at mealtimes only, right alongside solid food. This creates a natural routine and keeps water from displacing milk feeds. A few sips after a bite of food helps your baby learn to wash food down and gets them used to the taste of plain water.
Use plain water at room temperature or slightly cool. There’s no need to boil water for a healthy baby over 6 months in areas with safe tap water, though you can if you prefer. Don’t add sugar, juice, or flavoring. The point is to build a habit of drinking plain water early.
If your baby pushes the cup away or lets water dribble out, don’t force it. Learning to drink from a cup is a motor skill that takes weeks of practice. Some babies take to it quickly, others need a month or more before they’re swallowing consistently rather than just chewing on the cup rim. Keep offering, keep it low pressure, and let your baby set the pace.
What Changes After 12 Months
Once your baby turns one, water intake can increase as whole milk (or a continued milk alternative) replaces formula or breast milk. Toddlers between 12 and 24 months generally do well with 1 to 4 cups of water per day, depending on activity level, climate, and how much water-rich food they eat. The gradual transition from milk-dominant hydration to water-dominant hydration happens naturally over the second year of life as solid food portions grow and milk feeds decrease.
By this point, your child should be comfortable with a cup. If you started practicing at 6 months, you’ll likely have a toddler who can handle a straw cup independently and is getting better with an open cup, even if “better” still means occasional puddles on the high chair tray.