Discount Calculator
Four ways to work a deal: percent off (with stacked second discounts), a straight dollar amount off, finding the original price from a sale price, and finding the percent between two prices. Plus one-tap 2-for-1, 3-for-2, and 4-for-3 deal equivalents. You always see the final price, what you save, and the true effective rate — all in your browser.
The stacked-discount trap
"Take an extra 20% off sale prices" sounds like 20% on top of the sale — and it is, but not the way most people add it up. If something is already 25% off and you take another 20%, you're not getting 45% off. The second cut applies to the smaller, already-discounted price, so the real total is 40% off. The gap grows with bigger discounts. The calculator's effective-discount figure always tells you the honest number.
Discount, saved, effective rate
Three numbers tell the whole story of a deal: the final price you'll pay, the amount saved in dollars, and the effective discount as a percentage of the original. The dollar saving is what hits your wallet; the effective percentage is what lets you compare two offers fairly, even when they're structured differently.
Related
- Personal finance hub — all our money calculators and guides
- Sales tax calculator — add or remove sales tax
- Tip calculator — gratuity and bill split
- Profit margin calculator — for the seller's side
FAQ
Is anything I enter sent to a server?
No. The calculator runs entirely in your browser — open DevTools → Network and confirm. Nothing you type is uploaded.
How do I calculate a percent-off price?
Multiply the price by (1 − discount). A 25% discount on $80 is 80 × 0.75 = $60, a $20 saving. The calculator does this for you and also shows the amount saved and the effective discount.
Do stacked discounts add up?
No — and this trips up a lot of people. Two discounts multiply, they don't add. "25% off, then an extra 20% off" is not 45% off — it's 1 − 0.75 × 0.80 = 40% off, because the second discount applies to the already-reduced price. The calculator's second discount field shows the true effective rate so you don't overestimate the deal.
What's the difference between a discount and a markdown?
Practically, nothing — both reduce a price by a percentage. "Discount" usually describes a deal offered to a buyer; "markdown" is the retailer's term for lowering a listed price. The math is identical, and this tool handles either.
Can I work out the original price from the sale price?
Yes — switch to the Find original mode. Enter the sale price and the percent off, and the calculator computes original = sale ÷ (1 − discount). A $60 item at 25% off was originally 60 ÷ 0.75 = $80. Note that it's a divide, not an add-back: adding 25% to $60 gives $75, which is wrong, because the 25% was taken from the larger original price.
How do I find what percent off a sale price is?
Use the Find the % mode: enter the original and sale prices and the discount is 1 − sale ÷ original. From $80 down to $60 is 1 − 60/80 = 25% off. If the "sale" price is higher than the original, the calculator tells you it's actually a price increase.
Is 2-for-1 really 50% off?
Per item, yes — if you wanted two. "2-for-1" means you pay for one of two items (50% off), "3-for-2" means you pay for two of three (33.3% off), and "4-for-3" means you pay for three of four (25% off). The catch is the quantity: a 3-for-2 deal on something you only needed one of isn't a discount, it's an upsell. The deal chips in % off mode set the equivalent rate so you can compare a multibuy against a straight markdown.