Tire Sizes Calculator

if($td_errors != 0) {$td_error_msg = “Please enter proper values!”;}
else
{
$total_td = ((2 * $_POST[‘td_section_width’] * $_POST[‘td_aspect_ratio’]) / 2540) + $_POST[‘td_rim_diameter’];
$view_total_td = ”   Tire Diameter = “.$total_td;
}
}
//–Effective Ratio————————————–
//Effective Ratio = (old tire diameter / new tire diameter) x original ratio
if($_POST[‘a’] == “er”)
{
$er_old_tire_diameter = $_POST[‘er_old_tire_diameter’];
$er_new_tire_diameter = $_POST[‘er_new_tire_diameter’];
$er_original_ratio = $_POST[‘er_original_ratio’];
$er_errors = 0;
if($_POST[‘er_old_tire_diameter’] == “”) {$er_errors++;}
else { if(!is_numeric($_POST[‘er_old_tire_diameter’])) {$er_errors++;} }
if($_POST[‘er_new_tire_diameter’] == “”) {$er_errors++;}
else { if(!is_numeric($_POST[‘er_new_tire_diameter’])) {$er_errors++;} }
if($_POST[‘er_original_ratio’] == “”) {$er_errors++;}
else { if(!is_numeric($_POST[‘er_original_ratio’])) {$er_errors++;} }

if($er_errors != 0) {$er_error_msg = “Please enter proper values!”;}
else
{
$total_er = ($_POST[‘er_old_tire_diameter’] / $_POST[‘er_new_tire_diameter’]) * $_POST[‘er_original_ratio’];
$view_total_er = ”   Effective Ratio = “.$total_er;
}
}
//–Equivalent Ratio————————————–
//Effective Ratio = ( new tire diameter /old tire diameter) x original ratio
if($_POST[‘a’] == “er2”)
{
$er2_old_tire_diameter = $_POST[‘er2_old_tire_diameter’];
$er2_new_tire_diameter = $_POST[‘er2_new_tire_diameter’];
$er2_original_ratio = $_POST[‘er2_original_ratio’];
$er2_errors = 0;
if($_POST[‘er2_old_tire_diameter’] == “”) {$er2_errors++;}
else { if(!is_numeric($_POST[‘er2_old_tire_diameter’])) {$er2_errors++;} }
if($_POST[‘er2_new_tire_diameter’] == “”) {$er2_errors++;}
else { if(!is_numeric($_POST[‘er2_new_tire_diameter’])) {$er2_errors++;} }
if($_POST[‘er2_original_ratio’] == “”) {$er2_errors++;}
else { if(!is_numeric($_POST[‘er2_original_ratio’])) {$er2_errors++;} }

if($er2_errors != 0) {$er2_error_msg = “Please enter proper values!”;}
else
{
$total_er2 = ($_POST[‘er2_new_tire_diameter’] / $_POST[‘er2_old_tire_diameter’]) * $_POST[‘er2_original_ratio’];
$view_total_er2 = ”   Equivalent Ratio = “.$total_er2;
}
}
//–Actual MPH————————————–
//Actual MPH = (new tire diameter / old tire diameter) x indicated_mph
if($_POST[‘a’] == “amph”)
{
$amph_old_tire_diameter = $_POST[‘amph_old_tire_diameter’];
$amph_new_tire_diameter = $_POST[‘amph_new_tire_diameter’];
$amph_indicated_mph = $_POST[‘amph_indicated_mph’];
$amph_errors = 0;
if($_POST[‘amph_old_tire_diameter’] == “”) {$amph_errors++;}
else { if(!is_numeric($_POST[‘amph_old_tire_diameter’])) {$amph_errors++;} }
if($_POST[‘amph_new_tire_diameter’] == “”) {$amph_errors++;}
else { if(!is_numeric($_POST[‘amph_new_tire_diameter’])) {$amph_errors++;} }
if($_POST[‘amph_indicated_mph’] == “”) {$amph_errors++;}
else { if(!is_numeric($_POST[‘amph_indicated_mph’])) {$amph_errors++;} }

if($amph_errors != 0) {$amph_error_msg = “Please enter proper values!”;}
else
{
$total_amph = ($_POST[‘amph_new_tire_diameter’] / $_POST[‘amph_old_tire_diameter’]) * $_POST[‘amph_indicated_mph’];
$view_total_amph = ”   Actual MPH = “.$total_amph;
}
}
//–Indicated MPH————————————–
//Indicated MPH = (old tire diameter / new tire diameter) x actual_mph
if($_POST[‘a’] == “imph”)
{
$imph_old_tire_diameter = $_POST[‘imph_old_tire_diameter’];
$imph_new_tire_diameter = $_POST[‘imph_new_tire_diameter’];
$imph_actual_mph = $_POST[‘imph_actual_mph’];
$imph_errors = 0;
if($_POST[‘imph_old_tire_diameter’] == “”) {$imph_errors++;}
else { if(!is_numeric($_POST[‘imph_old_tire_diameter’])) {$imph_errors++;} }
if($_POST[‘imph_new_tire_diameter’] == “”) {$imph_errors++;}
else { if(!is_numeric($_POST[‘imph_new_tire_diameter’])) {$imph_errors++;} }
if($_POST[‘imph_actual_mph’] == “”) {$imph_errors++;}
else { if(!is_numeric($_POST[‘imph_actual_mph’])) {$imph_errors++;} }

if($imph_errors != 0) {$imph_error_msg = “Please enter proper values!”;}
else
{
$total_imph = ($_POST[‘imph_old_tire_diameter’] / $_POST[‘imph_new_tire_diameter’]) * $_POST[‘imph_actual_mph’];
$view_total_imph = ”   Indicated MPH = “.$total_imph;
}
}
//===============================================
$content = ‘

‘;

$content = addslashes($content);
$content = “\$result=\””.$content.”\”;”;
eval($content);
print stripslashes($result);
[/insert_php]