By the Numbers. According to the National Sleep Foundation, newborns should sleep 12 to 18 hours out of every 24 (every new parent hopes), with a gradual reduction to 12 to 14 hours for toddlers ages 1 to 3; 11 to 13 hours for preschoolers 3 to 5; and (yes!) 10 to 11 hours for schoolchildren ages 5 to 10.