I am facing some problems in property analysing calculations

[Weam Banna]

Hello everyone, in the past few weeks I have been practicing property analyzing, but as a beginner I am facing a small problem with some calculations (ROI, COCROI.. ) since I was given different formulas from different sources. So the question is, can an expert or a skilled person in analyzing give me the formulas of the basic things he/she uses in property analyzing(COCROI, ROI, net return on investment and annual cash flow). Plus a brief explanation of how to obtain them. Thank you in advance