Duration of courses: hours to weeks and self-study time I'm trying to apply for a Master's program and on the application form I have to list all subjects I have taken for my Bachelor's degree. For each one, they are asking for the duration in weeks and then Lectures (hrs./week), Tutorials (hrs./week) and Practical courses (hrs./week). 

In the documents I have from my university, the duration is only given in hours and the number of weeks taken for a single subject can vary greatly. Some may have been in the form of a block within two weeks, some have been spread over 10 weeks.
Is there any common conversion from hours to weeks? I'm sure they are only interested in the total time spent on this subject, not in the number of weeks in which I actually had lectures on it.

Secondly, my current university lists lecture time and self-study time, which added together make up the total course time (workload). As far as I can see, this self-study time does not match any of the three categories given. Should I just leave it out / substract it?
Regarding your first question for a "common conversion":

In Germany, workload for a course is measured in "hours per week in a semester" (abbr. "SWS" for Semesterwochenstunden), which would be what you are looking for. For singular events without a weekly schedule or for events where you need to calculate from a fixed number of hours, you can use the average (14 weeks / semester) or the real (12w / summer semester, 16w / winter semester [in Germany]) number of weeks and if needed the "academic hour" (which officially lasts only 45 minutes here) to calculate back.

As an example: A short practical course in the winter semester goes over 4 days with a daily workload of 6 full hours (breaks etc. already substracted).
This corresponds to 6 * 4 / 0.75 = 32 academic hours. As the semester has 16 weeks, the 32 hours correspond to 2 "SWS" or hours/week.

Formula: full hours [/ 0.75 if needed] / #weeks = hours per week

Covering your second question: 

If your current university includes "self-study" time in the total course time, I would also stick to that in calculating the final "hours/week" for the course. Although it might be confusing if some course include self-study in the total course time and others don't, you should not alter the official course time given by your university.