Desired ratio of total cholesterol/HDL should be

HDL-cholesterol level HDL level above 60 mg/dl protects against hea disease. Hence HDL is "good" cholesterol. A level below 40 mg/dl increases the risk of CAD. For every 1 mg/dl drop in HDL, the risk of hea disease rises 3%. If the ratio of total cholesterol / HDL is more than 3.5, it is dangerous. Similarly, LDL: HDL ratio more than 2.5 is also detrimental.Ref: DM Vasudevan - Textbook of Biochemistry, 8th edition, page no: 295