NUMFMT(1) User Commands NUMFMT(1)
NAME
numfmt - Convert numbers from/to human-readable strings
SYNOPSIS
numfmt [OPTION]... [NUMBER]...
DESCRIPTION
Reformat NUMBER(s), or the numbers from standard input if none are spec-
ified.
Mandatory arguments to long options are mandatory for short options too.
--debug
print warnings about invalid input
-d, --delimiter=X
use X instead of whitespace for field delimiter
--field=FIELDS
replace the numbers in these input fields (default=1); see FIELDS
below
--format=FORMAT
use printf style floating-point FORMAT; see FORMAT below for de-
tails
--from=UNIT
auto-scale input numbers to UNITs; default is 'none'; see UNIT
below
--from-unit=N
specify the input unit size (instead of the default 1)
--grouping
use locale-defined grouping of digits, e.g. 1,000,000 (which
means it has no effect in the C/POSIX locale)
--header[=N]
print (without converting) the first N header lines; N defaults
to 1 if not specified
--invalid=MODE
failure mode for invalid numbers: MODE can be: abort (default),
fail, warn, ignore
--padding=N
pad the output to N characters; positive N will right-align; neg-
ative N will left-align; padding is ignored if the output is
wider than N; the default is to automatically pad if a whitespace
is found
--round=METHOD
use METHOD for rounding when scaling; METHOD can be: up, down,
from-zero (default), towards-zero, nearest
--suffix=SUFFIX
add SUFFIX to output numbers, and accept optional SUFFIX in input
numbers
--to=UNIT
auto-scale output numbers to UNITs; see UNIT below
--to-unit=N
the output unit size (instead of the default 1)
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
UNIT options:
none no auto-scaling is done; suffixes will trigger an error
auto accept optional single/two letter suffix: 1K = 1000, 1k = 1000,
1Ki = 1024, 1M = 1000000, 1Mi = 1048576,
si accept optional single letter suffix: 1k = 1000, 1K = 1000, 1M =
1000000, ...
iec accept optional single letter suffix: 1K = 1024, 1k = 1024, 1M =
1048576, ...
iec-i accept optional two-letter suffix: 1Ki = 1024, 1ki = 1024, 1Mi =
1048576, ...
FIELDS supports cut(1) style field ranges:
N N'th field, counted from 1
N- from N'th field, to end of line
N-M from N'th to M'th field (inclusive)
-M from first to M'th field (inclusive)
- all fields
Multiple fields/ranges can be separated with commas
FORMAT must be suitable for printing one floating-point argument '%f'.
Optional quote (%'f) will enable --grouping (if supported by current lo-
cale). Optional width value (%10f) will pad output. Optional zero
(%010f) width will zero pad the number. Optional negative values (%-10f)
will left align. Optional precision (%.1f) will override the input de-
termined precision.
Exit status is 0 if all input numbers were successfully converted. By
default, numfmt will stop at the first conversion error with exit status
2. With --invalid='fail' a warning is printed for each conversion error
and the exit status is 2. With --invalid='warn' each conversion error
is diagnosed, but the exit status is 0. With --invalid='ignore' conver-
sion errors are not diagnosed and the exit status is 0.
EXAMPLES
$ numfmt --to=si 1000
-> "1.0k"
$ numfmt --to=iec 2048
-> "2.0K"
$ numfmt --to=iec-i 4096
-> "4.0Ki"
$ echo 1K | numfmt --from=si
-> "1000"
$ echo 1K | numfmt --from=iec
-> "1024"
$ df -B1 | numfmt --header --field 2-4 --to=si
$ ls -l | numfmt --header --field 5 --to=iec
$ ls -lh | numfmt --header --field 5 --from=iec --padding=10
$ ls -lh | numfmt --header --field 5 --from=iec --format %10f
AUTHOR
Written by Assaf Gordon.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/numfmt>
or available locally via: info '(coreutils) numfmt invocation'
Packaged by Debian (9.7-3)
Copyright © 2025 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/li-
censes/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
GNU coreutils 9.7 June 2025 NUMFMT(1)
Generated by dwww version 1.16 on Tue Dec 16 04:44:56 CET 2025.