Get the file URL from ACF, including file type and size

acf_get_file.php

/**
 * Get ACF File
 *
 * @param  string   $key     – the ACF field key
 * @param  string   $post_id – the ID of the post (if empty, will use $post->ID)
 * @return string   The image URL
**/
function get_acf_file( $key = 'file', $post_id = '' ) {
	if($post_id == ''):
		global $post;
		$post_id = $post->ID;
	endif;

	$file = get_field($key, $post_id);

	if( !empty($file) ):
		$file_url = $file['url'];
		$file_type = get_file_type($file['mime_type']);

		$file_size = get_file_size($file_url);
	endif;

	$file_details = array(
		'url'  => $file_url,
		'type' => $file_type,
		'size' => $file_size
	);

	return $file_details;
}

/**
 * Get File Size
 *
 * @param  string   $file_url     – passing in a file-type string
 * @return string   File type
**/
function get_file_size( $file_url ) {

    $file_info = array_change_key_case( get_headers($file_url, TRUE) );
    $file_size = file_size_convert( $file_info['content-length'] );

    return $file_size;
}

/**
 * Convert Filesize
 *
 * @param  string   $bytes     – bytes of
 * @return string   File type
**/
function file_size_convert($bytes) {
    $bytes = floatval($bytes);
        $arBytes = array(
            0 => array(
                "UNIT" => "TB",
                "VALUE" => pow(1024, 4)
            ),
            1 => array(
                "UNIT" => "GB",
                "VALUE" => pow(1024, 3)
            ),
            2 => array(
                "UNIT" => "Mb",
                "VALUE" => pow(1024, 2)
            ),
            3 => array(
                "UNIT" => "kB",
                "VALUE" => 1024
            ),
            4 => array(
                "UNIT" => "B",
                "VALUE" => 1
            ),
        );

    foreach($arBytes as $arItem)
    {
        if($bytes >= $arItem["VALUE"])
        {
            $result = $bytes / $arItem["VALUE"];
            $result = str_replace(".", "," , strval(round($result, 0)))."".$arItem["UNIT"];
            break;
        }
    }
    return $result;
}

/**
 * Get File Type
 *
 * @param  string   $mime_type     – passing in a file-type string
 * @return string   File type
**/
function get_file_type( $mime_type ) {

    if( preg_match('/msword/', $mime_type) || preg_match('/officedocument\.wordprocessingml\.document/', $mime_type) ):
        $type = 'MS Word';
    elseif(preg_match('/pdf/', $mime_type)):
        $type = 'PDF';
    elseif(preg_match('/ms-powerpoint/', $mime_type) || preg_match('/officedocument\.presentationml/', $mime_type) ):
        $type = 'Powerpoint';
    endif;

    return $type;
}