Original Price = Sale Price / Difference

Here’s an example: $50 / (1 – 0.2 = 0.8) = $62.50

The sale price is $50. The discount is %20 percent. First we subtract the discount 0.2 from 1 resulting in 0.8. Dividing the sale price by that number results in the original price of $62.50.

Here’s another example with a nice round result for clarification.

15% Off: $170 / (1 – 0.15) = $200

eg: $170 / 0.85 = $200