Discrepancy between values in htop and /proc/meminfo

From the author of htops answer https://stackoverflow.com/questions/41224738/how-to-calculate-system-memory-usage-from-proc-meminfo-like-htop/41251290#41251290 I got to know that the total memory in htop is calculated from /proc/meminfo. I think I could crosscheck this in code as well and it checks out. However compared to memory bar in htop. I see a major difference in the memory values shown in /proc/meminfo. In my /proc/meminfo the memory consumption reads MemTotal: 4144807288 kB MemFree: 3513532764 kB MemAvailable: 3936769368 kB Buffers: 1119392 kB So the Total used memory , which I think represented by the memory bar should be MemTotal-MemFree in GBs which should be (4144807288-3513532764)/1024^2=602Gb as far as I understand. However for me this value shows almost 180Gb. Could anyone explain how the values in /proc/meminfo and one in htop would become different.