How Do You Define a Toddler?

Toddler playing with blocks
Weekend Images Inc/istock

There's no shortage of child development experts, but there's simply no consensus about what constitutes a toddler. Unlike terms such as "infant," or "teen," the term has no absolute, agreed-upon meaning. That said, however, virtually every book, website, and presentation about early childhood development includes the term "toddler" and assumes a cultural understanding of what the term means.

The Origins of the Term 'Toddler'

The term toddler comes from the way that children first walk, which is at first unsteady and more like a "toddle" than actual walking. Given this, some people define a toddler as an infant who's able to walk. Of course, typically developing children walk at different ages, some before they turn 1 year old and others longer after age 2. Many children quickly acquire the ability to walk and run with good coordination, while others take longer to gain gross motor skills. Accordingly, experts have different, and sometimes conflicting, opinions about when toddlerhood actually begins and ends.

Defining the Term 'Toddler'

The American Academy of Pediatrics book, "Caring for Your Baby and Young Child," indicates that toddlerhood begins with the second year of life, after a child's first birthday.

"Your baby enters her second year and becomes a toddler, crawling vigorously, starting to walk, even talking a little," the book states.

 "Caring for Your Baby" notes that toddlerhood also includes children between the ages of 2 and 3 years old.

"Although your toddler's growth rate will slow between his second and third birthdays, nevertheless he will continue his remarkable physical transformation from a baby to a child," according to the American Academy of Pediatrics.

At age 3, the book states, a small child is "no longer a toddler." Instead, a child of this age is considered a preschooler, even though children younger than 3 often attend preschool (and many children never attend preschool at all.

This perspective on toddlerhood is echoed by the Centers for Disease Control and Prevention (CDC), which states toddlers are "1 to 2 years of age." The beloved, "What to Expect During the Toddler Years," also states that toddlerhood includes the second and third years of a child's life.

What to Expect From Your Toddler

Toddlers grow and change rapidly. If they meet developmental guidelines appropriately, they will gain a huge range of new skills. According to the CDC:

During the second year, toddlers are moving around more and are aware of themselves and their surroundings. Their desire to explore new objects and people also is increasing. During this stage, toddlers will show greater independence, begin to show defiant behavior, recognize themselves in pictures or a mirror, and imitate the behavior of others, especially adults and older children. Toddlers also should be able to recognize the names of familiar people and objects, form simple phrases and sentences, and follow simple instructions and directions.

There is a fairly wide age range during which toddlers meet certain milestones. If your child seems to be slower than most toddlers to gain the kinds of skills described above, they may simply be developing at their own rate. They may also, however, have developmental challenges that should be addressed as early as possible. If you have concerns about your toddler's development, talk with your pediatrician.


Centers for Disease Control and Prevention. Toddlers: 1-2 Years. Web. 2017.

Murkoff, Heidi,  Murkoff and Eisenberg Hathaway.Sandee. "What to Expect: The Toddler Years." USA: What to Expect LLC, 2009.

Shelov, Steven, et al. "Caring for Your Baby and Young Child." USA: American Academy of Pediatrics. 2009.