Calculating Discount Percentage of a given discounted price

Question

I am trying to find out the discount amount of a price.

The cost of item WAS £50.00 Sale Price £25.00 Discount = %50

However when use this formula below in PHP it doesnt give me the correct Discount percentage.

$percent = $rowx->Orgprice - $rowx->SalePrice / 100;
$percent =  50 - 25 / 100 = 49.75; 
$percent =  50 - 20 / 100 = 49.8;

All above percentages are wrong.

Answer 1

Use this formula for calculating the discount percentage :

Discount%=(Original Price - Sale price)/Original price*100

Translating it into code, it should be something like :

$percent = (($rowx->Orgprice - $rowx->SalePrice)*100) /$rowx->Orgprice ;

Answer 2

selling price = actual price - (actual price * (discount / 100))

So for example if (actual price) = $15, (discount) = 5%

selling price = 15 - (15 * (5 / 100)) = $14.25