Convert Seconds to Minutes PHP

$seconds = 60;

echo "seconds = $seconds<br />";

 $start_seconds = round($seconds);

 if($start_seconds <60)

 {

  $minutes ="";

  $seconds = $start_seconds;

 }

 else

 {

  $minutes = floor($start_seconds/60);

  $seconds = $start_seconds - $minutes*60;

  $minutes = "$minutes"."m";

  $seconds = $seconds."s";

 }

 echo "$minutes $seconds";