According to the "Quick Facts about Potty Training" (URL below):  
 
* You can begin training at any age, but your child's biology, skills, and readiness will determine when he can take over his own toileting.
 
* It takes three to twelve months from the start of training to daytime toilet independence. The more readiness skills that a child possesses, the quicker the process will be.
 
* No matter the age that toilet training begins, most children become physically capable of independent toileting between ages two and a half and four.
 
I have known children who took a lot longer, had accidents at five, six, seven, but have since been just fine.

Hi Mommasharp, In addition to the info you received from another parent...
 
I want to let you know that Education.com has a link to a free potty training kit on this page of the site:
http://www.education.com/topic/preschool-readiness/
 
Many preschools require that a child be potty trained before enrollment (or that the child be far along in the potty training process), and you'll find tips to help you and your child in the above resource center.
 
Good luck!

i wou;d say around 2

IVE BEEN TOLD IT WILL HAPPEN WHEN THE CHILD IS READY. IM STILL WAITING FOR MY SON TO BE FULLY TRAINED...

Hello,  
 
When your child reach the age of one year old and half.  she or he should be ready for the potty trained.  I trained my daughter at the age of one and half year old.  Depend on the child if she or he ready.