Understandability is a key concept in every system maintenance on the design phase. In the classification of the Inheritance multiple inheritance hierarchy is a typical task to identify the class understandability and system understandability. Some of the understandability metrics were already existed but they are giving the large complexity values while measuring a system or a class. In this research paper we proposed new metrics for class and system understandabilities. These metrics poses the lowest complexity values when comparing with existed metrics. This helps the designers of the system in easy way of understanding the system and get better designs of the systems in future.