i would say 5 years +,
5 years would be normal if you study hard, alot and commited, and also you practice alot of tactics and positions etc..
Other then that i think it would take 5 years + just to achieve master strength, if you do not study hard but study enough.
How long does it take the average person to achieve chess greatness? If one where to study as if he/she was going to school or a university to learn; what would be the average time it would take someone to become a GM?