Calculator Wizard
How to Calculate a Discount
A discount reduces a price by a given percentage. The math is straightforward once you break it into two steps: find the dollar amount the discount represents, then subtract it from the original price.
Worked Example
Example: $80 item, 25% off
Step 1: Convert 25% to decimal → 25 ÷ 100 = 0.25
Step 2: Discount amount = $80 × 0.25 = $20.00
Step 3: Sale price = $80 − $20 = $60.00
Stacking Multiple Discounts
A common mistake is adding two discount percentages together — assuming "25% off, then an extra 10% off" means 35% off total. It doesn't. Each discount applies to the already-discounted price, not the original, so stacked discounts are always smaller in total than simply adding the percentages.
Example: $100 item, 25% off, then an additional 10% off
Step 1: Apply 25% off → $100 × (1 − 0.25) = $75.00
Step 2: Apply 10% off the new price → $75 × (1 − 0.10) = $67.50
The final price is $67.50 — a total discount of 32.5%, not 35%. Stacked percentage discounts always add up to slightly less than their sum, because the second discount is calculated on a smaller base. The order doesn't matter, either — mathematically, applying 25% then 10% gives the exact same final price as applying 10% then 25%, since both are just multiplying the price by the same two factors regardless of sequence.
A quick distinction worth knowing: a discount reduces a price by a percentage, while a markup increases a cost by a percentage to set a selling price — they're mathematical mirror images of each other.
Working from the seller's side instead?
Try the Markup Calculator