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What was the original price before 20% off, if the sale price is 80?

Answer 100

A sale price of 80 after 20% off corresponds to an original price of 100.

Typical results show up to two decimal places; ≈ marks rounding. Very small or large results use up to three significant digits.

How to calculate it

80 ÷ (1 − 20 ÷ 100) = 100

  1. Divide the discount, 20, by 100.
  2. Subtract that fraction from 1.
  3. Divide the sale price, 80, by the remaining fraction to get 100.

Adding the discount percentage back to the sale price does not undo a discount. A 100% discount cannot be reversed because it erases the original price.

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