[SOLVED] Calculate Percentage Discount

[stevesimo]

Hi, I have a field which holds a numerical value lets say 29.99

 

Based on whatever the value of this number is I then want to calculate 5% of the value

 

Do I just do $discountPrice = $totalPrice * 5%

 

Im not sure what syntax to use to achieve this

 

Thanks

 

Steve

[per1os]

$discountPrice = ($totalPrice * .05);

[grimmier]

This should do the trick

$discountPrice = ($totalPrice - ($totalPrice * 0.05))

 

Here is a little test to see.

 

<?php 
$totalPrice = 100;
$discount = ($totalPrice * 0.05);
$discountPrice = ($totalPrice - ($totalPrice * 0.05)); 
echo $totalPrice; 
echo '<br><br>'.$discount; 
echo '<br><br>'. $discountPrice; ?>

 

I might even recommend doing some rounding and do it like this, since dealing with money values.

 

 <?php 
$totalPrice = 100;
$discount = round(($totalPrice * 0.05),2);
$discountPrice = ($totalPrice - $discount); 
echo $totalPrice; 
echo '<br><br>'.$discount; 
echo '<br><br>'. $discountPrice; ?>

[grimmier]

$discountPrice = ($totalPrice * .05);

 

 

that will only show how much is discounted not what the new price is after the discount, you need to subtract the discount amount from the initial price to get the discounted price.

[per1os]

Obviously, as you wrote out a whole segment, I simply answered the question being asked, what is the correct syntax. Obviously the % is not correct syntax.

 

I bet he is grateful that you went above and beyond.