Кодировка 1251 в UTF

<?php
error_reporting(E_ALL | E_STRICT);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);
header('Content-type: text/html; charset=UTF-8');
?>

<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>


<?php
if (isset($_POST['text'])) {

$encoding = $_POST['text'];
$encoding = str_replace('Р°', 'а', $encoding);
$encoding = str_replace('Р±', 'б', $encoding);
$encoding = str_replace('РІ', 'в', $encoding);
$encoding = str_replace('Рі', 'г', $encoding);
$encoding = str_replace('Рґ', 'д', $encoding);
$encoding = str_replace('Рµ', 'е', $encoding);
$encoding = str_replace('С‘', 'ё', $encoding);
$encoding = str_replace('Р¶', 'ж', $encoding);
$encoding = str_replace('Р·', 'з', $encoding);
$encoding = str_replace('Рё', 'и', $encoding);
$encoding = str_replace('Р№', 'й', $encoding);
$encoding = str_replace('Рє', 'к', $encoding);
$encoding = str_replace('Р»', 'л', $encoding);
$encoding = str_replace('Рј', 'м', $encoding);
$encoding = str_replace('РЅ', 'н', $encoding);
$encoding = str_replace('Рѕ', 'о', $encoding);
$encoding = str_replace('Рї', 'п', $encoding);
$encoding = str_replace('СЂ', 'р', $encoding);
$encoding = str_replace('СЃ', 'с', $encoding);
$encoding = str_replace('С‚', 'т', $encoding);
$encoding = str_replace('Сѓ', 'у', $encoding);
$encoding = str_replace('С„', 'ф', $encoding);
$encoding = str_replace('С…', 'х', $encoding);
$encoding = str_replace('С†', 'ц', $encoding);
$encoding = str_replace('С‡', 'ч', $encoding);
$encoding = str_replace('С€', 'ш', $encoding);
$encoding = str_replace('С‰', 'щ', $encoding);
$encoding = str_replace('СЉ', 'ъ', $encoding);
$encoding = str_replace('С‹', 'ы', $encoding);
$encoding = str_replace('СЊ', 'ь', $encoding);
$encoding = str_replace('СЌ', 'э', $encoding);
$encoding = str_replace('СЋ', 'ю', $encoding);
$encoding = str_replace('СЏ', 'я', $encoding);

$encoding = str_replace('Рђ', 'А', $encoding);
$encoding = str_replace('Р‘', 'Б', $encoding);
$encoding = str_replace('Р’', 'В', $encoding);
$encoding = str_replace('Р“', 'Г', $encoding);
$encoding = str_replace('Р”', 'Д', $encoding);
$encoding = str_replace('Р•', 'Е', $encoding);
$encoding = str_replace('РЃ', 'Ё', $encoding);
$encoding = str_replace('Р–', 'Ж', $encoding);
$encoding = str_replace('Р—', 'З', $encoding);
$encoding = str_replace('Р', 'И', $encoding);
$encoding = str_replace('Р™', 'Й', $encoding);
$encoding = str_replace('Рљ', 'К', $encoding);
$encoding = str_replace('Р›', 'Л', $encoding);
$encoding = str_replace('Рњ', 'М', $encoding);
$encoding = str_replace('Рќ', 'Н', $encoding);
$encoding = str_replace('Рћ', 'О', $encoding);
$encoding = str_replace('Рџ', 'П', $encoding);
$encoding = str_replace('Р ', 'Р', $encoding);
$encoding = str_replace('РЎ', 'С', $encoding);
$encoding = str_replace('Рў', 'Т', $encoding);
$encoding = str_replace('РЈ', 'У', $encoding);
$encoding = str_replace('Р¤', 'Ф', $encoding);
$encoding = str_replace('РҐ', 'Х', $encoding);
$encoding = str_replace('Р¦', 'Ц', $encoding);
$encoding = str_replace('Р§', 'Ч', $encoding);
$encoding = str_replace('РЁ', 'Ш', $encoding);
$encoding = str_replace('Р©', 'Щ', $encoding);
$encoding = str_replace('РЄ', 'Ъ', $encoding);
$encoding = str_replace('Р«', 'Ы', $encoding);
$encoding = str_replace('Р¬', 'Ь', $encoding);
$encoding = str_replace('Р', 'Э', $encoding);
$encoding = str_replace('Р®', 'Ю', $encoding);
$encoding = str_replace('РЇ', 'Я', $encoding);

echo $encoding;
echo '<br><br><br>';
}
?>

<form action="" method="POST">
    <textarea name="text"></textarea><br>
    <button type="submit" name="add">Add</button>
</form>

</body>
</html>