Many parents are unsure about when to start toilet training or "potty training. Instead of using age, look for signs that your child may be ready to start heading for the potty, such as being able to:. Most children begin to show these signs when they're between 18 and 24 months old, though some may not be ready until later than that. And boys often start later and take longer to learn to use the potty than girls. There are some times when you may want to put off starting toilet training, such as:.