How many wins do I need to get from Bronze 2 to Diamond?

With a 55% win rate, you need to play 760 games, win 418 of them and lose 342.

With a 60% win rate, you need to play 380 games, win 228 of them and lose 152.

With a 65% win rate, you need to play 253 games, win 164 of them and lose 89.

With a 70% win rate, you need to play 190 games, win 133 of them and lose 57.