$ free -m
              total        used        free      shared  buff/cache   available
Mem:           1986          51        1864           1          70        1825

$ free
              total        used        free      shared  buff/cache   available
Mem:        2033760       52264     1909584        1108       71912     1869628
Swap:        999420           0      999420

$ egrep "MemTotal|DirectMap2M" /proc/meminfo
MemTotal:        2033760 kB
DirectMap2M:     2054144 kB

$ vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  0      0 1909344  13988  57928    0    0    31     0   19   37  0  0 100  0  0

$ top -b -n 1 | grep Mem
KiB Mem :  2033760 total,  1906228 free,    52836 used,    74696 buff/cache
KiB Swap:   999420 total,   999420 free,        0 used.  1867664 avail Mem

Handle 0x0085, DMI type 6, 12 bytes
Memory Module Information
        Socket Designation: RAM socket #0
        Bank Connections: None
        Current Speed: Unknown
        Type: EDO DIMM
        Installed Size: 2048 MB (Single-bank Connection)
        Enabled Size: 2048 MB (Single-bank Connection)
        Error Status: OK

$ sudo dmesg | egrep "Memory|Free|ACPI" | egrep -v "edge|wakeup|noapic|Added|Bug|IRQ|pnp|Plug"
[    0.000000] BIOS-e820: [mem 0x000000007fee0000-0x000000007fefefff] ACPI data
[    0.000000] BIOS-e820: [mem 0x000000007feff000-0x000000007fefffff] ACPI NVS
[    0.000000] ACPI: Early table checksum verification disabled
[    0.000000] ACPI: RSDP 0x00000000000F6A10 000024 (v02 PTLTD )
[    0.000000] ACPI: XSDT 0x000000007FEEB683 00005C (v01 INTEL  440BX    06040000 VMW  01324272)
[    0.000000] ACPI: FACP 0x000000007FEFEE73 0000F4 (v04 INTEL  440BX    06040000 PTL  000F4240)
[    0.000000] ACPI: DSDT 0x000000007FEEC923 012550 (v01 PTLTD  Custom   06040000 MSFT 03000001)
[    0.000000] ACPI: FACS 0x000000007FEFFFC0 000040
[    0.000000] ACPI: FACS 0x000000007FEFFFC0 000040
[    0.000000] ACPI: BOOT 0x000000007FEEC8FB 000028 (v01 PTLTD  $SBFTBL$ 06040000  LTP 00000001)
[    0.000000] ACPI: APIC 0x000000007FEEC1B9 000742 (v01 PTLTD  ? APIC   06040000  LTP 00000000)
[    0.000000] ACPI: MCFG 0x000000007FEEC17D 00003C (v01 PTLTD  $PCITBL$ 06040000  LTP 00000001)
[    0.000000] ACPI: SRAT 0x000000007FEEB77F 000880 (v02 VMWARE MEMPLUG  06040000 VMW  00000001)
[    0.000000] ACPI: HPET 0x000000007FEEB747 000038 (v01 VMWARE VMW HPET 06040000 VMW  00000001)
[    0.000000] ACPI: WAET 0x000000007FEEB71F 000028 (v01 VMWARE VMW WAET 06040000 VMW  00000001)
[    0.000000] ACPI: Local APIC address 0xfee00000
[    0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[    0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0x7fffffff]
[    0.000000] ACPI: PM-Timer IO Port: 0x1008
[    0.000000] ACPI: Local APIC address 0xfee00000
[    0.000000] Using ACPI for processor (LAPIC) configuration information
[    0.000000] ACPI: HPET id: 0x8086af01 base: 0xfed00000
[    0.000000] Memory: 2011544K/2096628K available (6196K kernel code, 1159K rwdata, 2848K rodata, 1408K init, 688K bss, 85084K reserved, 0K cma-reserved)
[    0.005465] ACPI: 1 ACPI AML tables successfully acquired and loaded
[    0.005475] ACPI: setting ELCR to 0200 (from 0e80)
[    0.044362] x86/mm: Memory block size: 128MB
[    0.046853] PM: Registering ACPI NVS region [mem 0x7feff000-0x7fefffff] (4096 bytes)
[    0.170037] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f])
[    0.178855] pci 0000:00:07.3: quirk: [io  0x1000-0x103f] claimed by PIIX4 ACPI
[    0.282772] ACPI: Enabled 2 GPEs in block 00 to 0F
[    0.995687] Freeing initrd memory: 17572K
[    1.085789] Freeing unused kernel memory: 1408K
[    1.085832] Freeing unused kernel memory: 1980K
[    1.085873] Freeing unused kernel memory: 1248K

$ cat /proc/meminfo
MemTotal:        2033760 kB
MemFree:         1906864 kB
MemAvailable:    1868300 kB
Buffers:           14720 kB
Cached:            50220 kB
SwapCached:            0 kB
Active:            45004 kB
Inactive:          28204 kB
Active(anon):       8308 kB
Inactive(anon):     1064 kB
Active(file):      36696 kB
Inactive(file):    27140 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:        999420 kB
SwapFree:         999420 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          8284 kB
Mapped:            14860 kB
Shmem:              1108 kB
Slab:              23996 kB
SReclaimable:       9756 kB
SUnreclaim:        14240 kB
KernelStack:        3052 kB
PageTables:         1348 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     2016300 kB
Committed_AS:      38852 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
HardwareCorrupted:     0 kB
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       42880 kB
DirectMap2M:     2054144 kB
DirectMap1G:           0 kB

Memory: 32818828K/33439808K available (5612K kernel code, 1083K rwdata, 1896K rodata, 1264K init, 832K bss, 620980K reserved, 0K cma-reserved)

man free

  --si   Use power of 1000 not 1024.

terrance@terrance-ubuntu:~$ free -m
              total        used        free      shared  buff/cache   available
Mem:           7977        1445        1122          29        5408        6156
Swap:          8241           0        8241

terrance@terrance-ubuntu:~$ free --si -m
              total        used        free      shared  buff/cache   available
Mem:           8168        1454        1176          30        5537        6331
Swap:          8439           0        8439

terrance@terrance-ubuntu:~$ free
              total        used        free      shared  buff/cache   available
Mem:        8168472     1454764     1176684       30508     5537024     6331692
Swap:       8439804           0     8439804