Linux Memory Utilization

Linux Memory Utilization

Hi, in my application manager show 99% physical memory utilization, when I check on the server it was just using 6% memory. After that I check using this formula 

Memory Utilization (%) = 100 -(((MemFree + Buffers + Cached)*100)/maxValue)

some example from command free -b
              total        used        free      shared  buff/cache   available
Mem:    16771756032  2264182784    99753984   590835712 14407819264 13780406272
Swap:    6442446848   170655744  6271791104

when I calculated using that formula the result was
Memory Utilization     = 100 - (((99753984 + 0 + 14407819264) * 100) / 16771756032)
                                    = 14.094

so why was may application manager show 99% instead of 14%?

I already tried using SSH instead of SMNP but still got the same result