# Determining a server's memory usage

> Check how much memory a server is using with the free command, and read its output in megabytes.

Source: https://helpcenter.ruachost.com/developers/linux/determining-a-servers-memory-usage/

**Determining a server's memory usage**\
Learn how to check memory usage statistics on a server using the `free` command.

This article explains how to determine memory usage on a server with the `free` command.

**Using the free command**\
To check memory usage statistics on a server, follow these steps:

1. Log in to the server via SSH.
2. At the command prompt, run the following command:

```
free -m
```

> **Note:**
For easier reading, use the `-m` option to display memory statistics in megabytes. To see the statistics in bytes, run `free` without the `-m` option.

**Interpreting the free command output**\
For example, consider this sample output from a server:

```
root@example.com:~# free -m
             total      used      free    shared   buffers    cached
Mem:          2003      1338       665         0       149      1015
-/+ buffers/cache:       172      1830
Swap:            0         0         0
```

At first glance, you might assume the server is using 1338 MB of RAM and has 665 MB free. However, the actual memory in use is 172 MB, and 1830 MB is available for applications.

Linux uses free memory for disk caching to improve performance. Memory shown in the buffers and cached columns is available immediately for applications, even though it appears as "used." By adding free memory (665 MB), buffers (149 MB), and cached memory (1015 MB), the total available memory is 1829 MB. The slight difference from the 1830 MB shown is due to rounding when using the `-m` option. Using `free` without `-m` (bytes) will give exact numbers.

**Tip**\
On newer Linux versions, it’s easier to see available memory for applications because the `free` command includes an `available` column. For example:

```
              total        used        free      shared  buff/cache   available
Mem:           7882        2465        2278         666        3138        4458
Swap:             0           0           0
```

In this case, 4458 MB of memory is available for applications.

**More information**\
For a humorous explanation of Linux memory usage, visit [Linux Ate My RAM](http://www.linuxatemyram.com/).