So you want to display the percentage of savings your customer is getting during a sale. Well here is a way to find the percentage of savings and display it to your customer the magneto product page.
Fire up your ftp and go to the following location: app/design/frontend/yourtheme/yourtheme/template/catalog/product/view/
Download and back-up the this file “price.phtml”.
Open up the file and look for this piece of code.
__('Regular Price:') ?>
Below this add the following:
echo "(save ".round($totalPercent)."%)";
This code gets the regular price, and the final price and calculates the percentage. It then echos it in a div called “savings”.
We then round the percentage up and display it on our magento product page. Finally, we close the “savings” div.
When you reload your page, you should see that the savings percentage is displayed on your magento shop for all users to see!