how to get the percentage of a quantity in php

I want to take the percentage of two numbers that I store in two variables, the first variable is my delivery counter on time and the second is my delivery counter out of time, the sum is done correctly but I do not know how to get the percentage of that total, I know that it's something very simple, with a rule of three basic arithmetic, but I'm interested in passing it to the code.

<?php
include('conexion.php');
$fecha1=$_POST['finicio'];
$fecha2=$_POST['ffin'];
$contat=0;$contft=0;
$query=mysql_query("SELECT factura, fechafactura, cliente, hrasalida, hraentrega, hrallegada,fechaentrega,horarecibido, chofer, vehiculo, direccion from facturacion where estatus='ENTREGA DOMICILIO' AND fechafactura >= '$fecha1' AND fechafactura <= '$fecha2' order by fechafactura DESC LIMIT 70");
$cont=mysql_num_rows($query);
if ($cont>0)
{

    while ($array=mysql_fetch_array($query))
    {
        $fefac=$array[1];
        $feent=$array[6];
        $recfac=$array[7];
        $hrini=$array[3];
        $hrfin=$array[4];
        $diferencias = strtotime($hrfin) - strtotime($hrini);   
        $mins=$diferencias/60;

             //HORARIO DE 8:30 A 1:30
            $horalimite=strtotime("18:00:00");
            $hentrega=strtotime($hrfin);

            $hora1=strtotime("08:30:00");
            $hora2=strtotime("13:30:00");           
            $hrecfac=strtotime($recfac);

            //HORARIO DE 1:30 A 18:00
            $hora3=strtotime("13:31:00");
            $hora4=strtotime("18:00:00");
            /*$hora5=("18:00:00");
              $horali=date($hora5);
              $horalimite2=date('H:i:s', strtotime($horali.' +19 hours'.' +30 minutes'));
              */
              $horali=date("18:00:00");
              $HL=strtotime($horali);
              $horalimite2=date("H:i:s",mktime(date("H",$HL)+19,date("i",$HL)+30,date("s",$HL)));             

            $f=date($fefac);
            $fechalimite=date('Y-m-d', strtotime($f.' +1 days'));

            $dia=date($fefac);
            $S=date("w", strtotime($dia));

            //HORARIO DE SABADO
            $hora5=strtotime("08:30:00");
            $hora6=strtotime("14:00:00");

            $f=date($fefac);
            $fechalimite2=date('Y-m-d', strtotime($f.' +2 days'));  

            if($S!="6")
            { 
            if($hrecfac>=$hora3 and $hrecfac<=$hora4) 
            {         
             if($hentrega>strtotime($horalimite2) or strtotime($feent)>strtotime($fechalimite))                              
              {
                 $status="<label class='bg2'>FUERA DE TIEMPO</label>";
                  $contft=$contft+1;
              }
              else
              {    
                $status="<label class='bg1'>A TIEMPO</label>";
                $contat=$contat+1;
              }
            }
            else if($hrecfac>=$hora1 and $hrecfac<=$hora2) 
            {
               if($hentrega>$horalimite or strtotime($feent)>strtotime($fefac))
                 {
                   $status="<label class='bg2'>FUERA DE TIEMPO</label>";
                    $contft=$contft+1;   
                 }
                  else
                  {    
                    $status="<label class='bg1'>A TIEMPO</label>";
                    $contat=$contat+1;
                  }
                }
              }           
         else
         {
             if($hrecfac>=$hora5 and $hrecfac<=$hora6)
             {
                if($hentrega>$horalimite or strtotime($feent)>strtotime($fechalimite2))                              
              {
                 $status="<label class='bg2'>FUERA DE TIEMPO</label>";
                  $contft=$contft+1;                 
              }
              else
              {    
                $status="<label class='bg1'>A TIEMPO</label>";
                $contat=$contat+1;
              }
            }   
         }

        echo'<tr><td>'.$array[0].'</td><td>'.$array[1].'</td><td>'.$array[2].'</td><td>'.$array[3].'</td><td>'.$array[4].'</td><td>'.$array[5].'</td><td>'.$array[6].'</td><td>'.$array[7].'</td><td>'.$array[8].'</td><td>'.$array[9].'</td><td>'.$array[10].'</td><td>'.$mins.'min'. '</td><td>'.$status.'</td></tr>';
    }
}

else
{
    echo'<tr><td>No hay registros</td></tr>';
}
echo '<table>';
/***************************************TERMINA FACTURAS*/
?>