In my experience with early-mid career hires: 3 months to get ramped up, after which you should be productive-but-slow. At 6 months you're productive, and know

In my experience with early-mid career hires: 3 months to get ramped up, after which you should be productive-but-slow. At 6 months you're productive, and know enough to be dangerous. At 12 months you're really cranking and delivering excellent value. So, that averages ~6 months to break-even on an average employee, 9-12 months if you include "duds" in the average.