oppure:
codice:
<?php
function getmicrotime(){
    list($usec, $sec) = explode(" ",microtime());
    return ((float)$usec + (float)$sec);
}
$tstart = getmicrotime();

//tuo codice

$tend = getmicrotime();
$totaltime = ($tend - $tstart);
printf("Pagina generata in in %f secondi",  $totaltime);
?>