I am studying direct mapping in cache. I understood the concepts like dividing into blocks and lines , tag directory etc. When solving numerical problems of finding main memory size or tag directory size I have no problem. What I understood is that, in cache we have a tag associated with each cache line ( neglecting valid/invalid and other bits ) and size of each line is equal to block size.
So size of cache should be - Tag Directory Size + Size of each line * No of lines .
But when the guy( here ) is not adding tag directory size to cache size. Why is it so? Or I misunderstood the concept?