How do you find the percentage off when you have the sale and regular price?

To find the percentage off when you have the sale price and the regular price, first subtract the sale price from the regular price to find the discount amount. Then, divide the discount amount by the regular price and multiply by 100 to convert it to a percentage. The formula is: ((\text{Regular Price} - \text{Sale Price}) / \text{Regular Price} \times 100). This will give you the percentage off the regular price.