How old were tony and Tia in escape to witch mountain?

While the exact ages of Tony and Tia in "Escape to Witch Mountain" are never explicitly stated in the original movie, here's what we know:

* Tony is older than Tia. He's often shown being more mature and responsible, taking the lead in many situations.

* They are teenagers. They are definitely not young children, and their actions and dialogue suggest they are in their teens.

Considering their maturity level and the movie's 1975 setting, it's likely:

* Tony: Around 16-17 years old.

* Tia: Around 14-15 years old.

However, this is just an educated guess based on the film's context.