Format bytes to best unit

format_bytes.php

<?php 
/**
 * @param int $bytes
 * @param int $precision
 * @param int $baseUnit 1024 or 1000
 * @return array
 */
function formatBytes($bytes, $precision = 2, $baseUnit = 1024)
{
    $unit = ['B','KB','MB','GB','TB','PB','EB'];
    
    if ($baseUnit == 1000) {
        $unit = array_map('strtolower', $unit);
    } else {
        $baseUnit = 1024;
    }

    $chosenUnit = floor(log($bytes, $baseUnit));

    return [
        'value' => round($bytes/pow($baseUnit, $chosenUnit), $precision),
        'unit' => $unit[$chosenUnit],
    ];
}