You can start offering your baby small sips of water at around 6 months old, right when solid foods enter the picture. Before that age, breast milk or formula provides all the hydration a baby needs. The goal at 6 months isn’t to get your baby drinking full cups of water. It’s to let them practice the skill of sipping while getting used to the taste, one teaspoon at a time.
Why Wait Until 6 Months
Babies younger than 6 months get every drop of hydration they need from breast milk or formula. Giving water before this age isn’t just unnecessary, it’s risky. Too much water dilutes a baby’s normal sodium levels and can lead to seizures, coma, brain damage, and in extreme cases, death. This is called water intoxication, and infants are especially vulnerable to it because their kidneys are still maturing and their bodies are small enough that even a few extra ounces can throw off their electrolyte balance.
The early warning signs of water intoxication include drowsiness, confusion, irritability, nausea, and muscle twitching. Because the brain is the organ most affected, behavioral changes are usually the first thing parents notice.
How Much Water to Offer
Between 6 and 12 months, the CDC recommends 4 to 8 ounces of water per day. That’s roughly half a cup to one cup total, spread across the day. Water at this stage is a complement to breast milk or formula, not a replacement. Offering a few sips with meals is plenty.
After your baby’s first birthday, water intake naturally increases as milk feeds decrease. You can be more generous with water at meals and snacks, but breast milk, formula, or whole cow’s milk still provides the bulk of their fluids and nutrition through age 2.
Choosing the Right Cup
The cup you pick matters more than you might think, and the classic hard-spout sippy cup isn’t the best choice. Traditional sippy cups encourage a suckling motion similar to a bottle, which can slow down healthy oral development. Prolonged sippy cup use has been linked to crooked teeth, bite problems, misaligned jaws, and even speech delays. The unhealthy mouth position the spout creates is the core issue, though sugary liquids pooling against teeth make things worse.
Pediatric therapists generally recommend two alternatives: an open cup or a straw cup.
- Open cups encourage more mature oral motor patterns. Your baby learns to control their jaw, tongue, and lips to manage the flow of liquid, which supports healthy swallowing and speech development. It’s messy at first, but it builds skills that sippy cups actively work against.
- Straw cups are a good companion option. They require a different sucking pattern than a bottle, and by age 2, most children can alternate comfortably between open cups and straw cups for all their drinking.
Look for a small cup that fits your baby’s mouth. Something that holds 1 to 2 ounces is ideal for early practice.
Teaching Open Cup Drinking
Start between 6 and 9 months by filling a small open cup with about 1 teaspoon of water. That’s it. A tiny amount means less mess and less risk of your baby getting overwhelmed by a rush of liquid. Hold the cup to your baby’s lips yourself and tip it gently so just a bit of water touches their mouth. They’ll likely dribble most of it out, and that’s completely normal.
Make sure your baby is sitting upright and well supported. Trunk and head stability are prerequisites for managing liquid safely, and most babies are developing this control right around the 6-month mark. If your baby is still wobbly in a high chair, give them a few more weeks before pushing cup practice.
Between practice sessions, let your baby hold empty cups during playtime. Gripping, tipping, and mouthing the cup all build familiarity and the hand coordination they’ll eventually need to drink independently. By 10 to 12 months, most babies can form a pincer grip and are getting more precise with their hand movements, which makes self-feeding and cup-holding much easier.
Teaching Straw Drinking
The pipette method is the simplest way to introduce a straw. Here’s how it works:
- Dip a regular straw into water and trap a small amount of liquid in the bottom by pressing your finger over the top end.
- Bring the straw toward your baby’s mouth and wait for them to open up.
- Once your baby takes the bottom end of the straw into their mouth, release your finger. The liquid drops gently onto their tongue.
After a few sessions, your baby starts connecting the straw with liquid and will begin to close their lips around it. From there, you can transition to a straw cup and let them practice drawing liquid up on their own. Some babies catch on in a day or two, others need a couple of weeks. Both timelines are normal.
Making Water Part of the Routine
The easiest way to build the habit is to offer a small cup of water at every meal. You don’t need to coax or encourage your baby to drink a certain amount. Just place the cup within reach (or hold it for younger babies) and let them take sips when they’re interested. Babies who are getting adequate breast milk or formula won’t be particularly thirsty, so don’t worry if they only take a sip or two.
Some babies resist the taste of plain water at first, especially if they’re used to the sweetness of breast milk or formula. This is normal and usually resolves with repeated, low-pressure exposure. Offering water at room temperature can help, since that’s closer to the temperature of breast milk. Avoid adding juice, sugar, or flavoring to make water more appealing. The goal is to build acceptance of plain water early.
Modeling helps too. Babies are natural imitators. Drinking from your own cup at mealtimes signals to your baby that this is what people do when they eat.
Signs Your Baby Is Well Hydrated
You don’t need to track exactly how many ounces of water your baby drinks, especially when breast milk or formula is still their main source of fluids. Instead, watch for signs that hydration is on track. A well-hydrated infant produces at least six wet diapers per day, has tears when crying, and has a moist mouth.
Early signs of dehydration include a dry or parched mouth, fewer tears, a sunken soft spot on the head, unusual fussiness, and excessive sleepiness. More concerning signs are sunken eyes, cool or discolored hands and feet, wrinkled skin, and urinating only once or twice a day. If you notice any of these, increasing fluid intake and contacting your pediatrician is the right move.
In hot weather or when your baby has a fever or diarrhea, offer water and breast milk or formula more frequently. These are the situations where babies are most likely to need extra fluids beyond their usual intake.