How Much Water Do Babies, Toddlers, and Kids Need?

How much water do your kids need to be drinking? The answer depends on a number of factors, like their age, sex, activity level, and what other things they eat and drink.

little girl drinking water from a plastic bottle

Water is an essential nutrient – we need it to survive. In fact, 45-75% of your body weight is made of water. Even a body water loss of 1-2% can have some serious consequences, including cognitive impairment

We’ve all heard the 8 glasses per day “rule”, but what are the guidelines when it comes to the littles in our lives? 

What does water do in the body?

With so much of your body being made up of water, it will probably come as no surprise how many roles water plays in everyday functions. 

Water helps regulate your body temperature, keeping you cool and warm.

It provides lubrication to your joints and organs, supports optimal functioning of your heart and circulatory system, provides structure to your cells and tissues, and works to move nutrients throughout your body.

Drinking enough water can also help support healthy weight maintenance. 

How much water do kids need?

A number of factors determine how much water your kids will need, such as age, sex, activity level, and what else they eat and drink.

Water is lost from the body via many physiological processes, like breathing, peeing, digestion, and sweating.

How much water is lost through these routes can vary between individuals based on the factors mentioned above.

Total water balance is strictly regulated by your body over each 24 hour period, but that doesn’t mean it’s not important to pay attention to how much you’re drinking. 

According to the Institute of Medicine (IOM), the average hydration requirements for children are as follows.

Note that “total hydration needs” refers to hydration that comes from a combination of water, other fluids, and moisture-rich foods in your child’s diet. The amount that should come directly from water each day is listed as well.

Babies, 1-3 years old

Total hydration needs: 6 cups (1300 mL)

→ 4 cups (900 mL) of this should come from water

Toddlers, 4-8 years old

Total hydration needs: 7 cups (1700 mL)

→ 5 cups (1200 mL) of this should come from water

Males, 9-13 years old

Total hydration needs: 10 cups (2400 mL)

→ 8 cups (1800 mL) of this should come from water

Males, 14-18 years old

Total hydration needs: 14 cups (3300 mL)

→ 11 cups (2600 mL) of this should come from water

Females, 8-13 years old

Total hydration needs: 9 cups (2100 mL)

→ 7 cups (1600 mL) of this should come from water

Females, 14–18 years old

Total hydration needs: 10 cups (2300 mL)

→ 8 cups (1800 mL) of this should come from water

Note that exclusively breastfed babies, especially under 6 months old, do not require additional water to meet their hydration needs. Water can be introduced with a sippy cup around 4-6 months old, but shouldn’t be offered until after your baby has breastfed. 

Other sources of hydration 

As indicated in the guidelines above, hydration can come from certain foods and other beverages in addition to water.

For instance, kids who drink milk can count some of this toward their hydration needs. Babies who are on formula will also receive fluids this way.

Additionally, most fruits and vegetables are high in water content and can also be counted when looking at overall water intake.

Here is a list of the water content of some commonly consumed foods and drinks:

  • Milk, melon, strawberries, watermelon, leafy greens, cucumber = 90-99% water
  • Fruit juice, yogurt, grapes, broccoli, apples, grapes, oranges = 80-89% water
  • Corn, baked potatoes, bananas, avocados, hard-boiled eggs = 70-79% water
  • Pasta, legumes, ice cream = 60-69% water
  • Meat and meat-like alternatives (e.g. hot dogs, ground beef) = 50-59% water
  • Pizza = 40-49% water
  • Bread, bagels = 30-39% water
  • Cake, biscuits = 20-29% water
  • Butter, raisins = 10-19% water
  • Nuts = 1-9% water

Signs of dehydration in kids

As important as it is to make sure your child is getting enough fluid, it’s also important to know what to look for in terms of dehydration symptoms.

The general rule of thumb is that when you’re thirsty, you’re already dehydrated.

Below are some other things to look for when assessing hydration status in your children.

For babies, look for a decline in wet diapers. Babies are more likely to become dehydrated if they’re not eating (drinking) well, and if they have vomiting or diarrhea from an illness. Check your baby’s skin, as the elasticity will decline when dehydrated. They may have a dry mouth, and a lack of tears. Dehydrated babies also tend to be more irritable and sleepy. 

For toddlers, look for dark-colored urine and an overall decrease in urine output. They may also have parched lips, dry mouth, cold or dry skin, low energy levels, and fatigue. 

Older children will be able to better communicate when they’re not feeling well, and if they’re thirsty. They may have a rapid heartbeat, feeling lethargic, and have dry lips and skin. Not having as much urine output as usual is also a good indicator of hydration needs. 

If you liked this post, check out some of our other Frequently Asked Question blogs:

For more tips on feeding babies well, get your copy of our E-book First Bites: The Definitive Guide to Baby-Led Weaning for Plant-Based Babies.

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