How Many Teeth Do Kids Have?

Teeth start growing out at about 5–8 months of age, sometimes earlier, sometimes later, varies with each child.

The two upper or lower front teeth tend to come out first, and the back molars usually show up at later at the 20 to 30 months of age.

So that being said, a 12 month old can have any between 0 to 20 teeth at the age of one. Each child develops differently.