function formatBytes($bytes, $precision = 2) { 
    $units = array('B', 'KB', 'MB', 'GB', 'TB'); 

    $bytes = max($bytes, 0); 
    $pow = floor(($bytes ? log($bytes) : 0) / log(1024)); 
    $pow = min($pow, count($units) - 1); 

    // Uncomment one of the following alternatives
    // $bytes /= pow(1024, $pow);
    // $bytes /= (1 << (10 * $pow)); 

    return round($bytes, $precision) . ' ' . $units[$pow]; 
} 

(摘自php.net，有很多其他的例子，但我最喜欢这个:-)

极其简单的函数来获取人类文件大小。

原始来源:http://php.net/manual/de/function.filesize.php#106569

复制/粘贴代码:

<?php
function human_filesize($bytes, $decimals = 2) {
  $sz = 'BKMGTP';
  $factor = floor((strlen($bytes) - 1) / 3);
  return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . @$sz[$factor];
}
?>

简单的函数

function formatBytes($size, $precision = 0){
    $unit = ['Byte','KiB','MiB','GiB','TiB','PiB','EiB','ZiB','YiB'];

    for($i = 0; $size >= 1024 && $i < count($unit)-1; $i++){
        $size /= 1024;
    }

    return round($size, $precision).' '.$unit[$i];
}

echo formatBytes('1876144', 2);
//returns 1.79 MiB

我成功地完成了以下功能，

    function format_size($size) {
        $mod = 1024;
        $units = explode(' ','B KB MB GB TB PB');
        for ($i = 0; $size > $mod; $i++) {
            $size /= $mod;
        }
        return round($size, 2) . ' ' . $units[$i];
    }

function convertToReadableSize($size)
{
  $base = log($size) / log(1024);
  $suffix = array("B", "KB", "MB", "GB", "TB");
  $f_base = floor($base);
  return round(pow(1024, $base - floor($base)), 1) . $suffix[$f_base];
}

只需要调用函数

echo convertToReadableSize(1024); // Outputs '1KB'
echo convertToReadableSize(1024 * 1024); // Outputs '1MB'

下面是一个使用log10的选项:

<?php

function format_number(float $d): string {
   $e = (int)(log10($d) / 3);
   return sprintf('%.3f', $d / 1e3 ** $e) . ['', ' k', ' M', ' G'][$e];
}

$s = format_number(9012345678);
var_dump($s == '9.012 G');

https://php.net/function.log10