NUMFMT(1) General Commands Manual NUMFMT(1)

# [NAME](#NAME)

numfmt - Convert numbers from/to human-readable strings

# [SYNOPSIS](#SYNOPSIS)

**numfmt** \[OPTION]... \[NUMBER]...

# [DESCRIPTION](#DESCRIPTION)

Convert numbers from/to human-readable strings

# [OPTIONS](#OPTIONS)

[**--debug**](#debug)

print warnings about invalid input

[**--grouping**](#grouping)

use locale-defined grouping of digits, for example 1,000,000 (which means it has no effect in the C/POSIX locale)

[**-d**, **--delimiter** *<X>*](#d)

use X instead of whitespace for field delimiter

[**--field** *<FIELDS>* \[default: 1\]](#field)

replace the numbers in these input fields; see FIELDS below

[**--format** *<FORMAT>*](#format)

use printf style floating-point FORMAT; see FORMAT below for details

[**--from** *<UNIT>* \[default: none\]](#from)

auto-scale input numbers to UNITs; see UNIT below

[**--from-unit** *<N>* \[default: 1\]](#from~2)

specify the input unit size

[**--to** *<UNIT>* \[default: none\]](#to)

auto-scale output numbers to UNITs; see UNIT below

[**--to-unit** *<N>* \[default: 1\]](#to~2)

the output unit size

[**--padding** *<N>*](#padding)

pad the output to N characters; positive N will right-align; negative 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

[**--header**\[=*<N>*\]](#header)

print (without converting) the first N header lines; N defaults to 1 if not specified

[**--round** *<METHOD>* \[default: from-zero\]](#round)

use METHOD for rounding when scaling

*Possible values:*

- up
- down
- from-zero
- towards-zero
- nearest

[**--suffix** *<SUFFIX>*](#suffix)

print SUFFIX after each formatted number, and accept inputs optionally ending with SUFFIX

[**--unit-separator** *<STRING>*](#unit)

use STRING to separate the number from any unit when printing; by default, no separator is used

[**--invalid** *<INVALID>* \[default: abort\]](#invalid)

set the failure mode for invalid input

*Possible values:*

- abort
- fail
- warn
- ignore

[**-z**, **--zero-terminated**](#z)

line delimiter is NUL, not newline

[**-h**, **--help**](#h)

Print help

[**-V**, **--version**](#V)

Print version

# [EXTRA](#EXTRA)

UNIT options:

\- none: no auto-scaling is done; suffixes will trigger an error

\- auto: accept optional single/two letter suffix:

1K = 1000, 1Ki = 1024, 1M = 1000000, 1Mi = 1048576,

\- si: accept optional single letter suffix:

1K = 1000, 1M = 1000000, ...

\- iec: accept optional single letter suffix:

1K = 1024, 1M = 1048576, ...

\- iec-i: accept optional two-letter suffix:

1Ki = 1024, 1Mi = 1048576, ...

\- FIELDS supports [cut(1)](/man/os/uutils/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 locale). 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 determined precision.

# [VERSION](#VERSION)

v(uutils coreutils) 0.12.0

2026-10-08

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Document: numfmt(1) from uutils 0.12.0-r2 (Chainguard OS)
Source: https://github.com/uutils/coreutils