Comment by bayindirh

The command you want to use is "free -m".

This is from another system I have close:

                   total        used        free      shared  buff/cache   available
    Mem:           31881        1423        1042          10       29884       30457
    Swap:            976           2         974

2MB of SWAP used, 1423 MB RAM used, 29GB cache, 1042 MB Free. Total RAM 32 GB.