If you have a 2-year-old child, you are aware that this is an exciting time of growth and development in their young lives. In this same way, the sleep of your 2-year-old may begin to change. The sleep of infants is very different from that of toddlers or older children, and 2-year-olds are right in the midst of this transition.
The average 2-year-old may sleep as much as 12 to 14 hours of sleep per day, most of which occurs at night. Many toddlers of this age may take one nap per day that lasts 1 to 2 hours. When your child is ready to start preschool, the amount of sleep may decrease slightly to 11 to 12 hours total. Most children no longer take naps by the time of kindergarten.
Durmer, JS et al. "Pediatric Sleep Medicine". Continuum. Neurol 2007; 13(3):153-200.