EASA:
Ground Theory is already around 1400 hours of Classroom in any professional Academy.
So count that at least 1.5 years of intensive classes without vacation.
Expect a minimum of 2 years to get your basic frozen ATPL in any good school that values knowledge above monkey questionbank teaching.
To get into a Transport Aircraft, count another 6 To 9 months minimum, from MCC to being line-checked.