Question: how many ounces should a 13 lb baby drink?
Answer: While some young babies may drink 24 ounces a day, others may need 32 ounces or more. The American Academy of Pediatrics (AAP) suggests that on average, your baby needs about 2 1/2 ounces of formula a day for every pound of body weight. 1﻿ So a 3-month-old baby weighing 13 pounds needs about 32 1/2 ounces a day.