Upenn and other 4 year universities say that they don’t admit tranfers who exceed 2 years of coursework at their current institutions but I’m wondering how many community college units Are too many? I’m majoring in computer science and I plan to transfer when I get my associates degree but i checked the upenn website and they say I need 4 courses calculus through differential equations, 2 of physics ,2 computer programing 5 of social sciences and humanities and as many engineering courses so I already know all I need but all those courses add up to +70 units!!! How am I supposed to complete all those courses without having too many units ? Please help me 
It sounds like you are counting CU a different way, if you have 70+ of them.
Penn CIS requires 40 course units (CU) to graduate with a Bachelor’s degree. Remember that at Penn, 1 class is 1 CU, even if it is five days per week. 40 CU is 4 years, going 2 semester’s per year, with 5 CU per semester.
You need to work with Penn to figure out which courses you can transfer to cover specific requirements, such as calculus 240, physics, CIS etc.
It may not matter how many credits you have. How long it will take to finish the degree may depend more on how long it will take to complete all of the requirements. My guess is that you will have to take at least 20 CU at Penn. The more specific requirements you can use your credits to cover, the more flexibility you will have with your remaining credits.
Thank you so much I was really confused