80% off $100 is a discount of $80, so the final sale price is $20. Use the calculator below to change the numbers, or read the step-by-step math.
Formula: $100 × 0.80 = $80 discount. Then $100 − $80 = $20 sale price.
80% off $100 is a discount of $80, so the final sale price is $20.
You save exactly $80. Your out-the-door price (before tax) drops from $100 to $20.
The sale price is $20. Math check: $100 − ($100 × 80/100) = $20.