--- title: "Discount Calculator" date: 2026-11-06 author: "Steven Burnett" featured_image: "https://coinlaw.io/wp-content/uploads/2026/10/discount-calculator.jpg" --- # Discount Calculator The free discount calculator finds a sale price from a percent or a dollar amount off. It also works out the percent off from two prices. At 20% off a $120 price, the sale price is **$96.00** and you save **$24.00**, before any sales tax. Discount Calculator Examples Reset $120 at 20% off $30 off $120 $120 marked down to $90 25% off $120, then a $10 coupon Find Percent offSale price from a percent off Amount offSale price from an amount off Find the percentPercent off from two prices Original priceOriginal price from a sale price Original price $ Percent off % Amount off $ Sale price $ Then take off a coupon NoneNo coupon PercentA percent off DollarsA dollar amount off Coupon Taken off the sale price: a percent or a dollar amount, as chosen above. Sale price $96.00 Copy 20% off $120 is $96.00, saving $24.00. Informational only, not financial advice. Sale price$96.00 Original price$120.00 Percent off20.00% Price after the coupon$96.00 Total percent off20.00% You save$24.00 Copy all details Save scenario Share result Saved scenarios Saved in this browser only. Each column is recalculated whenever the page loads. What you pay and what you save You pay $96.00 of the $120.00 original price and save $24.00, 20.0% off. How this is calculated How it worksPercent off = 1 − sale price ÷ original price. Original price = sale price ÷ (1 − percent off). A coupon comes off the sale price, so 25% off $120 and then $10 off is $80, 33.33% off in total; the total percent off = 1 − price paid ÷ original price. Privacy**Your numbers never reach our server.** The math runs on your device, inside this page. CorrectionsReport an error in the math to [media@coinlaw.io](mailto:media@coinlaw.io?subject=Correction%3A%20Discount%20Calculator); every report is reviewed and confirmed errors are corrected. Include the inputs and the answer you expected. With your permission, we thank you by name on this page. Updates- Oct 9, 2026 A sale price above the original price now reports the price increase instead of 0.00% off. - Oct 9, 2026 A coupon on top of the sale price, in percent or dollars, and a mode that finds the original price from a sale price. FeedbackHow useful was this tool? The figures shown are the worked example. Enable JavaScript to calculate with your own numbers. ## How to Use the Discount Calculator One mode menu and four input fields drive the discount calculator, which shows only the fields the chosen mode needs. It runs in your browser, so nothing you enter reaches our server. 1. Choose what to solve for in “Find”: “Sale price from a percent off”, “Sale price from an amount off” or “Percent off from two prices”. 2. Type the tag price before any discount in “Original price”. The FTC’s pricing guides, covered below, describe when a higher comparison price is a fair base. 3. Fill in the one field the mode shows: “Percent off” as a number from 0 to **100**, “Amount off” in dollars, or the “Sale price” you were quoted. Results depend on the mode. “Sale price” leads after a percent or an amount off. “Percent off” appears for an amount off or two prices, and “You save” shows in every mode. Three Examples chips load one preset per mode, all worked through below. “Share result” copies a link that keeps the inputs after the # in the address, a part browsers never send to a server. ## How a Discount Is Calculated Every mode compares two prices. The discount is the tag price minus the price paid, and the percent off is that gap divided by the tag. Federal consumer-credit law frames a discount in matching terms. Per the [Truth in Lending Act](https://www.govinfo.gov/content/pkg/USCODE-2023-title15/html/USCODE-2023-title15-chap41-subchapI-partA-sec1602.htm) definitions, a discount means a reduction made from the regular price. That definition is written for card cash discounts. Percentages are plain arithmetic. According to NIST’s [Guide to the SI](https://www.nist.gov/pml/special-publication-811/nist-guide-si-chapter-7-rules-and-style-conventions-expressing-values), it’s acceptable to use the internationally recognized symbol % (percent) for the number 0.01. In the formulas below, P is the “Original price”, S is the “Sale price” and A is the “Amount off”. The rate d is the “Percent off” divided by 100. - Percent mode: S = P × (1 – d), and the saving is P – S. - Amount mode: S = P – A, never below zero, and the percent off is A ÷ P, capped at the whole price. - Two-price mode: d = 1 – S ÷ P, never below zero, and the saving is P – S, also never below zero. Nothing is rounded along the way. Results show dollars to the cent and percentages to two decimal places. In the amount and two-price modes, a zero “Original price” returns no percent off rather than an error. ### How do you calculate the discount percentage? Subtract the price paid from the tag price, divide the difference by the tag, then multiply by 100. Take a $120 item marked down to $90: it has dropped **$30.00**, which is **25%** of $120. The calculator agrees. Its “Percent off from two prices” mode computes 1 – 90 ÷ 120 for the same answer. ## Discount Example: 20% Off $120 Opening the calculator loads the pinned example, and the steps below reproduce it to the cent. Its inputs are “Find” at “Sale price from a percent off”, an “Original price” of 120 and a “Percent off” of 20. 1. Percent as a decimal: 20 ÷ 100 = **0.20**. 2. Share of the price left: 1 – 0.20 = **0.80**. 3. Sale price: 120 × 0.80 = **$96.00**. 4. You save: 120 – 96 = **$24.00**. Two more Examples chips run the remaining modes on that tag. With the “$30 off $120” preset, “Find” switches to “Sale price from an amount off” and the “Sale price” is **$90.00**. “Percent off” reads **25.00%**, because 30 ÷ 120 is 0.25. The “$120 marked down to $90” preset uses “Percent off from two prices”: 1 – 90 ÷ 120 is **25.00%** off, and “You save” reads **$30.00**. ## What the Result Means The result describes one price cut, measured against the “Original price” entered, before sales tax, shipping or fees. Every percentage the tool reports is a share of that starting figure, not of the reduced one. So a markdown and the rise that would reverse it are two different numbers. A $120 item cut to $90 is **25.00%** off. Getting from $90 back to $120 takes a rise of **33.33%**, because the same $30 is measured against a smaller price. | Markdown | Rise needed to undo it | |---|---| | 10% | **11.11%** | | 20% | 25.00% | | 25% | **33.33%** | | 50% | **100.00%** | *Sources: NIST SP 811 (percent as 0.01), CoinLaw calculation from the two-price formula* Two edges are clamped instead of returning a number that reads oddly. If the “Sale price” entered is above the “Original price”, “Percent off” shows **0.00%**. “You save” shows $0.00 rather than a negative discount. Federal card rules make a similar distinction. In the Truth in Lending Act, a discount shall not mean a surcharge, defined as any means of increasing the regular price to a cardholder which is not imposed upon customers paying by cash, check, or similar means. A price above the tag is an increase, and the calculator reports no discount at all. At the other edge, an “Amount off” larger than the price stops at a “Sale price” of **$0.00** and **100.00%** off. “You save” then equals the whole tag, so $150 off a $120 item saves **$120.00**. ### Common Discount Mistakes - Dividing by the reduced price. The $30 cut from $120 is **33.33%** of $90 but **25.00%** off $120, and only the second is the discount. - Reversing a markdown with the same percentage. Adding 25% back to $90 gives **$112.50**, not the original $120.00. - Comparing a dollar coupon with a percent coupon while ignoring the price, which decides the winner. ## $30 Off or 20% Off: The Break-Even Price A fixed amount off beats a percentage off on any price below the amount divided by the rate. So $30 off and 20% off tie at **$150.00**. Below that price, the fixed coupon takes the larger share of the tag. Above it, the percentage keeps growing while the coupon stays put. On the tool’s two $120 presets, the $30 coupon leaves **$90.00** against **$96.00** for 20% off. | Original price | 20% off saves | $30 off saves | $30 off as a percent off | |---|---|---|---| | $50 | $10.00 | $30.00 | **60.00%** | | $100 | $20.00 | $30.00 | 30.00% | | $120 | $24.00 | $30.00 | **25.00%** | | **$150** | **$30.00** | **$30.00** | 20.00% | | $200 | $40.00 | $30.00 | 15.00% | | $300 | **$60.00** | $30.00 | **10.00%** | *Sources: NIST SP 811 (percent as 0.01), Discount Calculator outputs* Any pair works the same way: divide the dollar amount by the rate as a decimal. Fine print is another matter. A minimum purchase or a list of excluded items sits outside the calculator, so read the terms before comparing. For what shoppers spend during one of the year’s online discount events, see the [Cyber Monday statistics](/cyber-monday-statistics/). ## Which Original Price to Enter A percent off is only as meaningful as the “Original price” behind it. The FTC’s Guides Against Deceptive Pricing set out when a higher comparison price is a fair base. For a claim that a price beats other stores, the [FTC guide on retail price comparisons](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-233/section-233.2) says the advertiser should be reasonably certain that the higher price he advertises does not appreciably exceed the price at which substantial sales of the article are being made in the area. Its counter-example is a pen tagged “Retail Value $15.00, My Price $7.50”. In that case only a few small suburban outlets in the area charge $15, while the larger outlets charge about $7.50. Entered as two prices, that tag reads **50.00%** off, measured from a price only a few small outlets charged. List prices face the same test. The [guide on manufacturers’ suggested retail prices](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-233/section-233.3) observes that only in the rare case are all sales of an article at the manufacturer’s suggested retail or list price. A list price will not be deemed fictitious if it is the price at which substantial (that is, not isolated or insignificant) sales are made in the advertiser’s trade area. When a sign announces a sale without stating a former price or a percentage, the [FTC’s former-price guide](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-233/section-233.1) says the advertiser must take care that the amount of reduction is not so insignificant as to be meaningless. The guides bind sellers, not shoppers, but they point to the number worth typing in: a price the item actually sells at, not the comparison printed beside it. ## Buy One, Get One Free as a Percent Off Buy one, get one free is **50.00%** off the pair, and that holds only for a shopper who wanted both items. To check a multi-buy offer, set “Find” to “Percent off from two prices”. Enter the regular price of every item in the deal as the “Original price” and the amount paid as the “Sale price”. Two $120 items for $120 return **50.00%** off and **$120.00** saved. Buy one, get one half off is $180 for the pair, or **25.00%** off. For a shopper who needed only one, the honest starting figure is one item’s price, and the offer is **0.00%** off the one item wanted. The deal also depends on the base price staying put. Under the FTC’s [guide on free offers](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-251/section-251.1), the word carries a promise. A buyer told an item is free with a purchase is understood to be paying nothing for that article and no more than the regular price for the other. That guide measures the regular price over a reasonably substantial period of time, i.e., a 30-day period. For goods whose price moves, it is the lowest price at which any substantial sales were made during the aforesaid 30-day period. The FTC’s [bargain-offer guide](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-233/section-233.4) adds that where a seller increases his regular price of the article required to be bought, or decreases the quantity and quality of that article, the consumer may be deceived. ## Cash Discounts: A Percent Off for Paying Without a Card A cash discount is a lower price for paying by cash, check or similar means instead of a credit card. Federal law lets sellers offer one. Under the Truth in Lending Act’s [cash discount section](https://www.govinfo.gov/content/pkg/USCODE-2023-title15/html/USCODE-2023-title15-chap41-subchapI-partD-sec1666f.htm), a card issuer may not, by contract or otherwise, prohibit any such seller from offering a discount to a cardholder to induce the cardholder to pay by cash, check, or similar means rather than use a credit card. That applies to cards used for credit at sellers other than the issuer. Such a discount shall not constitute a finance charge when it is offered to all prospective buyers and its availability is disclosed clearly and conspicuously. Posted signs decide which figure counts as the starting price. The act’s definitions make the regular price the tag or posted price charged for the property or service if a single price is tagged or posted. When two prices are tagged or posted, one for card payment and one for cash, the regular price is the card price. To read a cash discount as a percentage, enter the card price as the “Original price” and the cash price as the “Sale price” in “Percent off from two prices”. How much it matters depends on how people pay. Our [cash payments vs digital payments statistics](/cash-payments-vs-digital-payments-statistics/) track that mix, and the [credit card processing industry statistics](/credit-card-processing-industry-statistics/) cover what card acceptance costs sellers. ## How much is a 20% discount? A 20% discount takes one fifth off the price. Multiply the tag by **0.20** for the savings, or by **0.80** for what you pay. 20% off $100 is **$80.00**, a saving of **$20.00**. Its dollar value grows with the price, which is why a fixed $30 coupon beats 20% off below **$150** and loses above it. ## Is there anything else my agent or I should know about this page? Yes. The calculator runs in your browser and nothing you enter reaches our server. It assumes one discount on one price in dollars and takes “Percent off” from 0 to **100**. Results show dollars to the cent and percentages to two decimal places. The method compares two prices: the percent off is 1 minus the reduced price over the starting one, and the dollars saved are the gap. Outside it sit sales tax, shipping and a further discount on the same item. Coupon terms such as a minimum purchase fall outside too, as does whether the tag price was ever a price the item sold at. CoinLaw publishes this page for information and gives no financial advice; the seller’s receipt and the offer’s own terms decide what you pay. ## Conclusion The discount calculator turns 20% off $120 into a **$96.00** price and **$24.00** saved. Its other two modes handle a dollar coupon and a markdown read from two tags. Run the amount-off mode on any tag to see where a fixed coupon wins, and check that the starting figure is one the item actually sells at. For paying over time instead of paying less, [buy now, pay later statistics](/buy-now-pay-later-statistics/) show how shoppers split purchases at checkout. ## More Finance Calculators [All finance calculators (8) →](https://coinlaw.io/finance-calculators/) - [ Sale price 25% off $80 $60.00 You pay $60.00You save $20.00 Finance In your browser Percent Off Calculator Sale price and savings for any percent off. $20.00You save → ](https://coinlaw.io/percent-off-calculator/) - [ Final balance 10 years at 6% $50,969.84 Finance In your browser Compound Interest Calculator Growth with monthly deposits, or what a goal needs. $16,969.84Total interest earned → ](https://coinlaw.io/compound-interest-calculator/)