* Course load: A full-time student typically takes 12-18 units per semester. If you're taking 15 units, that's almost a full-time load, so it could be completed in one semester.
* Course intensity: Some courses require more time and effort than others. A heavier course load of difficult classes might take longer, even if it's technically 15 units.
* Summer sessions: If your college offers summer sessions, you could complete some of the units during the summer, potentially reducing the overall time.
* Part-time vs. Full-time: If you're a part-time student, it will take longer than one semester.
In short, while a full-time student could theoretically complete 15 units in one semester, it's not a guaranteed timeframe. It could easily take longer depending on the factors above.