Discount Calculator
Calculate the final price after a discount, how much you save, or what the original price was before a markdown.
All three panels update automatically as you type.
Discount math has three directions and people get confused about which they need. "30% off $120" is the easy one. "The sale price is $84, what was the original?" requires dividing by (1 - discount rate), which is the direction most people get wrong. And "the item was $120, now it is $84, what percent off is that?" is a simple subtraction-then-divide that still trips people up. All three covered here.
To find the original price from a sale price: divide by (1 - discount rate). A $84 sale price at 30% off: $84 / 0.70 = $120. The wrong approach — adding 30% back to $84 — gives $109.20, which is wrong.
Stack discounts
Two discounts do not add. A 20% discount followed by a 10% discount is not 30% off. It is 20% off first, then 10% off the reduced price. On a $100 item: 20% off = $80, then 10% off $80 = $72. That is 28% off the original, not 30%. Retailers sometimes advertise stacked discounts in ways that obscure this. The final price is always (1 - d1) x (1 - d2) x original price.
Frequently asked questions
How do I calculate a tip on top of a discounted price?
Calculate the tip on the pre-discount price if you want to tip on the service value, or on the post-discount price if you want to tip on what you actually paid. Most etiquette guides for restaurant tipping suggest tipping on the pre-discount price, especially for coupons or promotional discounts where the server provided full service.