Display on Product List >>
step by step
1. Open file
app/design/frontend/package_name/theme_name/template/catalog/product/price.phtml
2. Right at the top, add the following code,
//get the actual product price
$_wasPrice = $_store->roundPrice($_store->convertPrice($_product->getPrice()));
//get the special product price $_specialPrice = $_store->roundPrice($_store->convertPrice($_product->getFinalPrice()));
3. Now calculate percentage of the discount price, basic maths people!
//calculate the percentage
$_discountPercentage = round( ( ( $_wasPrice - $_specialPrice ) / $_wasPrice ) * 100 ) . '%';
4. You may simply echo your discount percentage variable under the class="special-price" div, do not be confused by seeing too many special-price div classes, to avoid confusion display your discount percentage on all the classes.
Display on Product View >>
step by step
...to be continued
Pretty simple, right lol... I hope this article was helpful to you, please leave your question/s on the comments section below and I will do my best to answer back.