$var is defined as 1 in the beginning:

while($hr >= $hrused) {
	while($exptotal <= $this->XP_table_needed[0][$var]) {
		$exptotal += $this->XP_table_gain[0][$var] + ($this->XP_table_gain[0][$var] * 0.33) + ($this->XP_table_gain[0][$var] * 0.3);
		$hrused ++;
	}
	$var ++;
}