size_format( int|string $bytes, int $decimals ): string|false

Converts a number of bytes to the largest unit the bytes will fit into.

Description

It is easier to read 1 KB than 1024 bytes and 1 MB than 1048576 bytes. Converts number of bytes to human readable number by taking the number of that unit that the bytes will go into it. Supports YB value.

Please note that integers in PHP are limited to 32 bits, unless they are on 64 bit architecture, then they have 64 bit size. If you need to place the larger size then what PHP integer type will hold, then use a string. It will be converted to a double, which should always have 64 bit length.

Technically the correct unit names for powers of 1024 are KiB, MiB etc.

Parameters

$bytesint|stringrequired
Number of bytes. Note max integer size for integers.
$decimalsintoptional
Precision of number of decimal places. Default 0.

Return

string|false Number string on success, false on failure.

More Information

Usage:
// Returns the string '1 KiB'
<?php $size_to_display = size_format(1024); ?>

Source

function size_format( $bytes, $decimals = 0 ) {
	$quant = array(
		/* translators: Unit symbol for yottabyte. */
		_x( 'YB', 'unit symbol' ) => YB_IN_BYTES,
		/* translators: Unit symbol for zettabyte. */
		_x( 'ZB', 'unit symbol' ) => ZB_IN_BYTES,
		/* translators: Unit symbol for exabyte. */
		_x( 'EB', 'unit symbol' ) => EB_IN_BYTES,
		/* translators: Unit symbol for petabyte. */
		_x( 'PB', 'unit symbol' ) => PB_IN_BYTES,
		/* translators: Unit symbol for terabyte. */
		_x( 'TB', 'unit symbol' ) => TB_IN_BYTES,
		/* translators: Unit symbol for gigabyte. */
		_x( 'GB', 'unit symbol' ) => GB_IN_BYTES,
		/* translators: Unit symbol for megabyte. */
		_x( 'MB', 'unit symbol' ) => MB_IN_BYTES,
		/* translators: Unit symbol for kilobyte. */
		_x( 'KB', 'unit symbol' ) => KB_IN_BYTES,
		/* translators: Unit symbol for byte. */
		_x( 'B', 'unit symbol' )  => 1,
	);

	if ( 0 === $bytes ) {
		/* translators: Unit symbol for byte. */
		return number_format_i18n( 0, $decimals ) . ' ' . _x( 'B', 'unit symbol' );
	}

	foreach ( $quant as $unit => $mag ) {
		if ( (float) $bytes >= $mag ) {
			return number_format_i18n( $bytes / $mag, $decimals ) . ' ' . $unit;
		}
	}

	return false;
}

Changelog

VersionDescription
6.0.0Support for PB, EB, ZB, and YB was added.
2.3.0Introduced.

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