I think if you're going by the "is able to go to the toilette, sit on it, wipe, get down and wash hands" by himself, most people don't fully train their child until they are about 5-6-years-old. Even if your child could do most of the above, just for the height issue, you'd often have to lift the child up onto the toilette when you're out of the house. I don't think many people hold to that standard when they consider their child potty trained. I would consider my son fully potty trained if 1) he could communicate that he had to go to the toilette all of the time--and make it to the toilette in time to go on the toilette 2) he never wore a diaper--even at nighttime. I know of several children who are already in elementary school and still wear pull-up diapers at night because they tend to wet the bed. I would still consider them potty trained, though.