Generally:
* Bachelor's Degree in Psychology: Most Bachelor's degrees in psychology require between 120 and 130 credit hours.
* Master's Degree in Psychology: Master's degrees typically require an additional 30-60 credit hours beyond a Bachelor's degree.
* Doctoral Degree in Psychology (Ph.D. or Psy.D.): Doctoral degrees are significantly longer programs, often requiring 60-90 credit hours *beyond* a Master's degree. This can take 4-7 years of full-time study.
To find the exact credit hour requirement, you must check the specific program requirements at the university or college you are interested in attending. Look for the program's curriculum or course catalog on the institution's website.