How big will my royal python grow two.?

I do not know its , its quite thin about 1.5 - 2 inch thick, about 2ft - 2ft 5 inch in length. i refuse to probe it as its unfair on the animal ( or popping ) its in a 4ft viv. i got it about 2 months ago. I think it is between 4 - 11 months old, but the shopkeeper did not know himself. i thought as it has spurs it might be a male, but now i know male's and female's have spurs. My royals spurs are about half a centimetre long and id imagine 1/8 of a centimetre thick. Someone please help as i am lost. any advice will be welcomed. thank you