size_format() │ WP 2.3.0

Converts bytes to a human-readable format: 500 B, 63 KB, 9 MB, 2 GB, 1 TB.

Formats file size into a readable format.

All file sizes in PHP are stored in bytes and obtained in them using filesize() or some other way. But it is much easier to read 1 KB than 1024 B.

The function takes the number of bytes and converts them to the amount of:

  • kilobytes (KB)
  • megabytes (MB)
  • gigabytes (GB)
  • terabytes (TB)
  • petabytes (PB)
  • exabytes (EB)
  • zettabytes (ZB)
  • yottabytes (YB)

Also, it is important to remember that the maximum integer on 32-bit systems is limited to 2147483647, while on a 64-bit system it is 9223372036854775807. Therefore, when you need to specify a number greater than the system can handle, specify the number as a string.

wp_convert_hr_to_bytes() — a similar function that, conversely, converts a shortened byte value to an integer byte value. For example, 1Mb is converted to 1048576.

Use this custom function to convert a large integer into a readable form 1500 >> 1.5 тыс..

Uses: number_format_i18n()
1 time — 0.000025 sec (very fast) | 50000 times — 0.11 sec (very fast) | PHP 7.0.8, WP 4.6

No Hooks.

Returns

String|false. A string or false if conversion failed.

Usage

size_format( $bytes, $decimals );
$bytes(int/string) (required)
The number of bytes to convert. Keep in mind that PHP has a maximum allowable size for integers, and it is small on 32-bit systems.
$decimals(int)
The number of digits after the decimal point.
Default: 0

Examples

0

#1 Byte conversion demonstration 

echo size_format( 99 );            //> 99 B
echo size_format( 9999 );          //> 10 KB
echo size_format( '9999' );        //> 10 KB
echo size_format( 9999, 2 );       //> 9,76 KB
echo size_format( 9999999 );       //> 10 MB
echo size_format( 9999999999 );    //> 9 GB
echo size_format( 9999999999999 ); //> 9 TB
0

#2 Display the size of a file in human-readable format 

$file_size = 1229; // filesize in bytes

echo size_format( $file_size, $decimals = 2 ); // 1.20 KB

Changelog

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

size_format() code WP 6.9

wp-includes/functions.php 
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;
}

Files data (get file info)

upload download (file system)

Formatting