The honest answer is months, not years — but only if you count the right thing. Most estimates measure exam levels. Holding a conversation is a lower bar than passing B1, and you reach it far sooner than the official hour counts suggest.
The official numbers, and what they miss
Institutions quote 600 to 750 hours for a language close to your own, and two to three times that for a distant one. Those figures describe reading, writing, listening and speaking together, assessed formally. Conversational ability is narrower. A few hundred words, the present tense and the confidence to keep going through mistakes will carry an ordinary conversation — and that combination arrives in months of regular speaking.
What actually moves the number
Speaking hours, not study hours. Two learners with identical vocabulary will differ enormously if one has spoken for fifty hours and the other for five. Frequency beats duration. Fifteen minutes daily outperforms two hours on Sunday, because speaking is partly a motor skill and it decays fast without contact.
A realistic target for most people: simple conversation about familiar topics within three to six months, given daily speaking practice. Without speaking practice, the number is effectively never.