Calculate Font Sizes

<?php
$parts = 6; // dont change, h1 to h6
$base_size = 12; //font-size inherited by parent element, just to see how much pixels the headings will be :)
$base_lh = 1.5; //line-height in em
$max_size = 300; //maximum font-size in percent (h1)
$min_size = 100; //minimum font-size in percent (h6)
 
$percent_per_part = 1 / ($parts -1);
$outputstring = 'h%d { margin-bottom:%sem; line-height:%sem; font-size:%s%%; /'.'* %spx *'.'/ }<br>';
 
$output = '';
for($i=1;$i<$parts+1;$i++) {    
    $y = 1 - (($i - 1) * $percent_per_part);
    $percent = (pow($y,2) * ($max_size - $min_size)) + $min_size;
    $mult = $percent / 100;
    $px = $mult * $base_size;
    $lh = $base_lh / $mult;
    $output .= sprintf($outputstring, $i, number_format($lh, 3, '.', ''), number_format($lh, 3, '.', ''), $percent, number_format($px, 1, '.', ''));
}
echo $output.'<br><br>';
?>