Just thought I'd share a very simple script. You set your estimated cpc, budget, payout and then the script calculates how many conversions you need to break even. You need to have PHP installed on your server, if you do, just upload it and the rest is pretty self explanatory.
PHP Code:
<?php
if ($_POST['cpc'] && $_POST['budget'] && $_POST['payout']) {
$cpc = $_POST['cpc'];
$budget = $_POST['budget'];
$payout = $_POST['payout'];
$clicks = $budget/$cpc;
$conversionsTBE = $budget/$payout;
$conversionRateTBE = $conversionsTBE/$clicks;
$conversionRateTBE = $conversionRateTBE*100;
$data = "You can afford apr. ".floor($clicks)." clicks. You need apr. ".floor($conversionsTBE)." converions to break even, a conversion rate of <b>".substr($conversionRateTBE, 0,3)."%</b><br />";
}
?>
<form method="post">
Esitmated CPC <input type="text" name="cpc" />
Your Budget <input type="text" name="budget" />
Offer Payout <input type="text" name="payout" />
<input type="submit" name="submit" value="Calculate!" />
</form>
<?php if ($data) { echo '<div style="border: 1px solid #000; background: green; padding: 5px; color: #fff;">'.$data.'</div>'; }
?>