Convert percent value to decimal value in PHP

$dec = $pct / 100.00;

// if you actually have a % sign in $pct strip it out
$pct = '15%';
$dec = str_replace('%', '', $pct) / 100.00;

function percentToDecimal($percent): float
{
    $percent = str_replace('%', '', $percent);
    return $percent / 100.00;
}

echo floatval("6.15%") / 100.00;