How Much Water Does My Baby or Toddler Need?

JanelMS, RD, LDN, CBS

What to know about giving your child water

  • Water should not be offered to babies under 6 months old

  • Breastmilk and infant formula provide adequate hydration for babies

  • Adding too much water to infant formula can be harmful

  • Water should be used for hydration mostly after your child is 1 year old

Water is an ideal beverage for hydration; however, medical experts agree that water should not be offered before 6 months of age.1

The American Academy of Pediatrics (AAP) and the Dietary Guidelines for Americans recommend infants be exclusively breastfed (or formula fed) for the first six months of life before introducing complementary foods and water.2,3

Water is not usually necessary in the first year of life as breastmilk and infant formula are comprised mostly of water and typically provide adequate hydration for your baby.4,18

Once your little one is around 6 months, small amounts of water can be introduced to help baby build a taste for water and to learn how to use an open cup.1

Read on to learn how much water you can offer your baby.

When can I start giving my baby water?

Small amounts of water can be introduced at or after 6 months of age.1

Introducing water before that time can put baby at risk for electrolyte imbalance as well as inadequate intake of breastmilk and or formula.6,7 Breastmilk and formula provide adequate hydration prior to 6 months, even in very hot climates.8

How much water can I give my baby?

Babies between 6 and 12 months need no more than 4 to 8 ounces of water each day.1

You can start by offering your baby small amounts of water at mealtimes in an open cup, sippy cup, or straw cup.1

Introducing water at this age is not about hydration, but more to help develop cup-drinking skills as well as introduce your baby to the taste of water. This is the first step in developing the life-long beneficial habit of drinking water.

This small amount of water is not supposed to replace baby’s milk intake, so be aware of how much water they’re drinking, as well as if it’s impacting how much breastmilk or formula they’re getting.

If it is impacting their milk intake, be sure to reduce how much water you’re offering, or have them drink it at a time that does not interfere with their intake of breastmilk, infant formula, or solid foods.

Never offer more than 8 ounces of water per day to your baby. When you first introduce water, don’t be surprised if your little one only has a few sips all day! As your infant gets closer to a year, they may start taking closer to the 8-ounce maximum recommendation.

Read more:

Transitioning to Cups for Babies and Toddlers

Is My Baby or Toddler Getting Enough Fluoride?

Wondering how to introduce water in a cup? Come chat with our team of registered dietitian nutritionists, fellow moms, and lactation specialists, available from Monday – Friday 8 am – 6 pm (ET). Chat now!

Can I add extra water when preparing infant formula?

In most cases, no. This practice should only be done if explicitly directed to do so by your child’s pediatrician.13

Occasionally, caretakers might add extra water to infant formula to make the formula last longer, but this can have very dangerous consequences.

The risks of diluting formula may include: electrolyte imbalance, inadequate caloric intake leading to poor growth, as well as other negative effects.9,10,11,12

It is important to prepare formula exactly according to package instructions unless otherwise directed by your child’s pediatrician.13

Read more:

Everything You Need to Know about How to Prepare and Store Infant Formula

Formula Preparation: What Type of Water Should I Use?

What if my baby is dehydrated?

In general, babies who have at least 5-6 good wet diapers in a 24-hour period are usually adequately hydrated.16,17

Signs of possible dehydration include:

  • Chapped lips

  • Few to no tears when crying

  • Sunken eyes

  • Parched dry mouth

  • Dark urine color

  • Sunken soft spot on top of the head 

  • Fussiness

  • Excessively sleepy15,17

Always consult with your baby’s pediatrician if you’re concerned about your baby being dehydrated. They will let you know the right steps to take to help your child should need more fluids.

Learn about: Dehydration in Kids: How to Keep your Baby or Tot Adequately Hydrated

How much water should toddlers drink?

At 12 months of age, it is recommended to stick with breastmilk and water for hydration, or if you were formula feeling to switch from formula to whole cow’s milk and water for hydration.14

A 1 to 2-year-old can have 1-4 cups* of water per day from a cup.1 You can offer water in cups at meal and snack times, and whenever your toddler indicates they may be thirsty.

*The exact amount of water needed per day depends on the total amount of milk consumed for the day.

For example, if your child doesn’t consume any milk (breastmilk or cow’s) for the day, then all 4 cups of their fluid needs should be met with plain water. However, if your child has 3 cups of milk per day, then they only need an additional 1 cup of water to meet their fluid needs.

Note that the American Academy of Pediatrics (AAP) recommends only 2 to 3 cups (16 to 24 ounces) of cow’s milk per day in total.1

Read more: What Type of Milk should my Toddler Drink?

Can my baby or toddler drink juice or other beverages?

Plain water gives your child all the hydration they need, while milk provides essential nutrients for growth and development.

There will likely be opportunities where your child is offered beverages other than milk and water, such as soda, juice, and sweetened beverages. It is best to avoid beverages with added sugars or artificial sweeteners.19,20

Occasionally, a small amount of 100% fruit juice is okay. The AAP recommends no more than 4oz per day in 1–3 year-olds.1 Juice can also be diluted with water.

Young children who are introduced to sweet drinks at a young age may develop a strong preference for them―making water and plain milk less desirable beverages.20

Read more: What to Drink Instead of Sweetened Beverages

Bottom Line

To help build strong, nourishing hydration habits from a young age, use these tips for guidance:

  1. Before 6 months: No extra water or additional beverages other than breastmilk or infant formula*

  2. After 6 months: Slowly work up to 4 to 8 ounces of water per day in an open cup, straw cup, or sippy cup

  3. After 1 year: 4 cups of fluid are needed per day, divided between water and whole cow’s milk (or breastmilk)

  4. Ages 1 to 3 years: Only 4 ounces of 100% fruit juice recommended per day

*Unless explicitly directed by your child’s pediatrician.

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For more on this topic, check out the following articles:

How Much Formula Does My Baby Need?

Introducing Solids: First Foods and Textures

Meal Plan for 6 to 9 Month Old Baby

Nutrient Needs and Feeding Tips for 6 to 12 Month Olds

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