He's never been a big drinker, and now that I'm working on taking him off the bottle, he drinks even less.
According to the Institute of Medicine’s Dietary Reference Intakes for Electrolytes and Water, the Adequate Intake (AI) for water for children aged 1 to 3 is 1.3 liters per day; that’s about 44 fluid ounces, or the equivalent of 5-1/2 8 ounce cups of water. Children can certainly drink plain water throughout the day to meet their daily fluid needs, but they’ll also get water by consuming other healthful beverages including milk and 100 percent fruit juice. About 20 percent of childrens’ daily water intake typically comes from foods that have a lot of moisture/water content including juicy fruits (such as watermelon), vegetables, cooked grains, and soups.
Just as for all of us, your child’s daily water needs will increase when the weather is warm or hot, and/or when your child is more physically active than usual. If your child’s urine is close to clear in color, that means he or she is likely adequately hydrated; if the urine appears concentrated or yellow in color, that may mean he or she needs to drink a bit more to meet his or her daily needs.