Discount Calculator
Free discount calculator. Enter an original price and a discount percentage to see exactly how much you save and the final sale price. Or switch to 'what % off' mode to find the discount from an original and sale price. Instant and fully in-browser.
Details
Result
How to use the Discount Calculator
- 1Enter the original, pre-discount price in the first field - the sticker or list price before any markdown.
- 2Pick a mode: to get the sale price, type the discount percentage; to get the discount, type the actual sale price instead.
- 3Read both results as you type - forward mode shows money saved and final price, reverse mode shows the discount percentage, with no button to press.
- 4Change the numbers to test what-ifs, such as nudging the percentage to see how far the final price moves.
- 5To stack two discounts, copy the resulting sale price into the original-price field and apply the second percentage - do not just add the two percentages together.
- 6Use the copy button to grab the final figure, or read it off the screen; nothing is saved, logged, or transmitted.
About the Discount Calculator
The Discount Calculator settles the two arithmetic questions that come up every time something is on sale: "What will I actually pay after this percentage off?" and "What percentage was knocked off this price?" In the forward mode, you enter an original price and a discount percentage, and it shows the money saved and the final sale price. In the reverse mode, you enter an original price and a sale price, and it derives the discount percentage between them. The formulas are deliberately plain and auditable: savings equal original price times percentage divided by 100, the final price is original minus savings, and the reverse percentage is (original minus sale) divided by original, times 100. Nothing is rounded in a hidden way and nothing is estimated. All of this arithmetic runs in your browser with JavaScript the instant you type. No price is uploaded, no server processes your numbers, and once the page has loaded the calculator keeps working with the connection off. Where it earns its keep is in the awkward cases that trip up mental math. Reverse mode lets you compare two sales advertised in different units, one as "30% off" and the other as "$25 off," by converting both to the same figure. Forward mode lets you check a coupon at the register before you pay, work out a promo price for something you are reselling, or see whether a percentage deal beats a flat-dollar one on a cheap item versus an expensive one. It also exposes the stacked-coupon trap: a 30% markdown followed by a 20% coupon is not 50% off, because the second discount applies to the already-reduced price. To model that here, run the forward calculation once, take the resulting sale price, and feed it back in as the new original before applying the second discount; the honest combined figure lands at 44%. Because every result appears as you type and nothing is stored, you can throw as many hypothetical prices at it as you want, and closing the tab wipes them all.
Frequently asked questions
I only know the original and sale price - how do I get the discount percentage?
Use reverse mode and enter both prices. The tool computes (original minus sale) divided by original, times 100. An item that fell from 80 to 60 shows 20 saved and a 25% discount - not 20%, because the 20 is measured against the original 80.
Can it handle a 30% sale stacked with a 20% coupon in one shot?
No, and that is deliberate, because the two do not add to 50%. Calculate the 30% off first, copy that sale price into the original-price field, then apply the 20%. The true combined discount is 44%, since the coupon only bites the already-reduced price.
Does it include sales tax or shipping?
No - it works on the item price and discount only. Discounts are normally applied before tax, so take the final price the tool gives you and add tax to that. Shipping is a separate flat charge you tack on afterward; it is not a percentage of the item.
What if I enter a discount above 100% or a sale price higher than the original?
A discount over 100% would push the final price below zero, which is meaningless, so keep percentages between 0 and 100. In reverse mode, a sale price above the original returns a negative percentage - that is a price increase or markup rather than a discount, which is a useful signal that you swapped the two fields.
Do my prices get sent anywhere or saved?
No. The arithmetic runs entirely in your browser in JavaScript, so the numbers never leave your device and nothing is uploaded, logged, or stored. After the page loads you can use it offline, and closing the tab clears every value you entered.
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Frequently asked questions
How do I calculate a discount?+
Multiply the original price by the discount percentage to get the amount saved, then subtract that from the original price for the final sale price.
How do I find what percent off something is?+
Use the 'What % off?' mode: enter the original price and the final (sale) price, and the calculator shows the discount percentage and the amount off.
Is the discount calculator free and private?+
Yes. It runs entirely in your browser with no sign-up — your numbers are never uploaded.