A desired cholesterol ratio is less than 3.5 to 1. The high density lipoprotein, or HDL, number is divided into the total cholesterol number in order to find the HDL cholesterol ratio, according to the Mayo Clinic.
Cholesterol ratios are used by health care professionals to monitor patients. However, the American Heart Association recommends using total cholesterol level numbers to help patients better understand their health status, states WebMD.
Cholesterol is a naturally occurring substance produced in the liver or received from food. Cholesterol performs important functions in the body, but when there is too much low density lipoprotein, or LDL, or too little HDL, the risk of heart attack or stroke becomes higher.