ls and stat are command-line tools in Linux you can use to display information about files and folders, including their sizes. du is another tool you can use to display size information, which is a dedicated tool created just for that purpose.

du can be used to find files or folders taking huge space in your system. You can use the info to delete offending files and folders and prevent your storage from becoming full. It is, however, not a tool to view disk usage information.

Related: How to check disk size and usage in Linux
Related: How to clear disk space on Linux

Steps to check the size of files and folders in Linux:

  1. Check file size of a file. 

    $ du Documents/random.txt  16	Documents/random.txt

    Default size unit is in 1K block.

  2. Display file size in human readable format. 

    $ du -h Documents/random.txt  16K	Documents/random.txt

    Size will automatically be displayed in K (Kilobytes), M (Megabytes), G (Gigabytes) or T (Terabytes) unit.

  3. Show the size of all folders recursively from within a directory. 

    $ du -h Documents/ 21M	Documents/Finance 4.0K	Documents/Secret/Empty 40K	Documents/Secret 21M	Documents/

  4. Set depth level for recursive folder size. 

    $ du -h --max-depth=1 Documents/ 21M	Documents/Finance 40K	Documents/Secret 21M	Documents/

  5. Show size of folders including total. 

    $ du -hc Documents/ 21M	Documents/Finance 4.0K	Documents/Secret/Empty 40K	Documents/Secret 21M	Documents/ 21M	total

  6. Show total size of folders or directories. 

    $ du -hs Documents/ 21M	Documents/

  7. Show system folder size using sudo. 

    $ sudo du -hs /var/cache/ [sudo] password for user:  117M	/var/cache/

  8. Show non-recursive directory size using wildcard. 

    $ sudo du -hs /var/cache/* 6.2M	/var/cache/apparmor 16M	/var/cache/app-info 75M	/var/cache/apt 6.1M	/var/cache/cracklib 32K	/var/cache/cups 5.2M	/var/cache/debconf 40K	/var/cache/dictionaries-common 2.7M	/var/cache/fontconfig 2.1M	/var/cache/fwupd 0	/var/cache/fwupdmgr 60K	/var/cache/ldconfig 2.1M	/var/cache/man 8.0K	/var/cache/PackageKit 8.0K	/var/cache/private 4.0K	/var/cache/realmd 2.2M	/var/cache/snapd

  9. Use du command with more available options to check file and directory size in Linux. 

    $ du --help Usage: du [OPTION]... [FILE]...   or:  du [OPTION]... --files0-from=F Summarize disk usage of the set of FILEs, recursively for directories.  Mandatory arguments to long options are mandatory for short options too.   -0, --null            end each output line with NUL, not newline   -a, --all             write counts for all files, not just directories       --apparent-size   print apparent sizes, rather than disk usage; although                           the apparent size is usually smaller, it may be                           larger due to holes in ('sparse') files, internal                           fragmentation, indirect blocks, and the like   -B, --block-size=SIZE  scale sizes by SIZE before printing them; e.g.,                            '-BM' prints sizes in units of 1,048,576 bytes;                            see SIZE format below   -b, --bytes           equivalent to '--apparent-size --block-size=1'   -c, --total           produce a grand total   -D, --dereference-args  dereference only symlinks that are listed on the                           command line   -d, --max-depth=N     print the total for a directory (or file, with --all)                           only if it is N or fewer levels below the command                           line argument;  --max-depth=0 is the same as                           --summarize       --files0-from=F   summarize disk usage of the                           NUL-terminated file names specified in file F;                           if F is -, then read names from standard input   -H                    equivalent to --dereference-args (-D)   -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)       --inodes          list inode usage information instead of block usage   -k                    like --block-size=1K   -L, --dereference     dereference all symbolic links   -l, --count-links     count sizes many times if hard linked   -m                    like --block-size=1M   -P, --no-dereference  don't follow any symbolic links (this is the default)   -S, --separate-dirs   for directories do not include size of subdirectories       --si              like -h, but use powers of 1000 not 1024   -s, --summarize       display only a total for each argument   -t, --threshold=SIZE  exclude entries smaller than SIZE if positive,                           or entries greater than SIZE if negative       --time            show time of the last modification of any file in the                           directory, or any of its subdirectories       --time=WORD       show time as WORD instead of modification time:                           atime, access, use, ctime or status       --time-style=STYLE  show times using STYLE, which can be:                             full-iso, long-iso, iso, or +FORMAT;                             FORMAT is interpreted like in 'date'   -X, --exclude-from=FILE  exclude files that match any pattern in FILE       --exclude=PATTERN    exclude files that match PATTERN   -x, --one-file-system    skip directories on different file systems       --help     display this help and exit       --version  output version information and exit  Display values are in units of the first available SIZE from --block-size, and the DU_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables. Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).  The SIZE argument is an integer and optional unit (example: 10K is 10*1024). Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000). Binary prefixes can be used, too: KiB=K, MiB=M, and so on.  GNU coreutils online help: <https://www.gnu.org/software/coreutils/> Full documentation <https://www.gnu.org/software/coreutils/du> or available locally via: info '(coreutils) du invocation'

    Related: du man page