100% Free — No Sign-Up Needed
Sigma Calculator — 80+ Free Tools
Find any sale price in seconds — enter the original price and the percent off to see exactly what you save and what you pay.
Using the Percent Off Calculator takes less than ten seconds, and there is nothing to install or sign up for. Start by typing the original price — the full sticker price before any reduction — into the “Original Price” field. Next, enter the advertised discount percentage into the “Discount” field; for a “25% off” sale you simply type 25. Press the blue Calculate button and the tool instantly displays two numbers: You Save, the dollar amount and percentage kept in your pocket, and Sale Price, the final amount you pay. The result panel appears the moment the page loads with the example values, and it updates every time you press Calculate with new numbers.
The Reset button restores the $100 and 20% example so you can start a fresh comparison at any time. Because every calculation runs entirely in your own browser, results appear instantly, keep working even if your connection drops after the page loads, and are never transmitted to any server — your shopping arithmetic stays completely private.
A few habits will make the tool even more useful. Always enter the pre-tax merchandise price: in most regions the discount comes off the subtotal first and sales tax is then charged on the reduced amount, so entering a tax-included price would understate your savings. When a sign advertises a range such as “20–40% off,” run the calculation at both ends of the range to see your best- and worst-case prices before you fall in love with an item. Use the calculator on your phone while standing in the aisle — mental math under bright store lights is exactly where costly mistakes happen. And remember that the tool computes the merchandise total: shipping fees, gift wrapping, assembly charges, and extended warranties are added afterward and are rarely discounted unless the promotion explicitly says so.
Reading the result panel is straightforward. The green You Save figure shows the discount in dollars followed by the percentage in parentheses, so you can confirm the store applied the rate it advertised. The navy Sale Price figure is the bottom line for the merchandise itself — the number to compare against competing stores, online listings, and your budget.
A percent off promotion reduces an item’s listed price by a stated percentage. The discount is the amount subtracted, almost always expressed as a percentage of the original price: “30% off” means the retailer removes a sum equal to thirty percent of the ticket price. The sale price is what remains — the amount you actually hand over at the register. Your savings are the difference between the two figures: the dollars that stay in your pocket instead of moving to the retailer’s till.
Retailers favor percent-off pricing for reasons that go beyond simple generosity, and the most important one is psychological. A percentage feels large on expensive items and small on cheap ones, which quietly nudges shoppers toward bigger carts. “50% off” a $200 jacket sounds dramatic and urgent, while the mathematically identical 50% percent off a $4 coffee reads as a trivial $2. The discount framing matters: “save $100” and “save 50%” describe the same deal on a $200 item, yet research on shopper behavior suggests the percentage version motivates more strongly at higher price points. Understanding the arithmetic behind the sign neutralizes this framing effect and lets you compare offers on equal terms.
Percent-off offers come in several flavors, and each needs slightly different math. A simple markdown (“25% off everything”) applies one percentage to the ticket price — the straightforward case this calculator solves. Tiered promotions (“take an extra 20% off clearance”) stack a second discount onto an already reduced price, and the two percentages do not simply add together, as the formula section below demonstrates. Fixed-amount coupons (“$10 off any $50 purchase”) are not percentage discounts at all: their effective percentage shrinks as your basket grows, so a $10 coupon equals 20% off a $50 order but only 5% off a $200 order. “Buy one, get one 50% off” is effectively 25% off two identical items — a conversion the signage rarely volunteers.
Finally, remember that the sale price printed on the shelf tag is only part of the story. Unit pricing — the cost per ounce, per sheet, or per load often printed in tiny type — can reveal that the flashiest discount is not actually the cheapest option on the shelf. And your total savings shrink whenever shipping, handling, or service fees are added after the markdown. Whenever a deal has more than one moving part, work through the steps in order, or let the calculator above handle the sequencing for you.
Every percent-off deal reduces to two short formulas. To find the sale price: Sale price = Original price × (1 − Discount ÷ 100). To find your savings: Savings = Original price − Sale price, which is the same as Original price × (Discount ÷ 100). In plain words, turn the percentage into a decimal, multiply by the original price to get the discount amount, and subtract that amount from the original price.
The same idea works in reverse whenever you need to audit a sign. If you know the original price and the sale price, the discount percentage is (Original price − Sale price) ÷ Original price × 100. And if you know the sale price plus the discount percentage, the original price is Sale price ÷ (1 − Discount ÷ 100). These three rearrangements cover every direction of the calculation, and the worked examples below show each of them in action.
Worked example 1. A pair of headphones lists at $149.99 and is marked 30% off. Step 1: convert 30% to the decimal 0.30. Step 2: the discount amount is $149.99 × 0.30 = $44.997, which rounds to $45.00. Step 3: the sale price is $149.99 − $45.00 = $104.99. You save $45.00 and pay $104.99. As a check, $104.99 ÷ $149.99 = 0.70, confirming that you pay 70% of the original — exactly what 30% off means.
Worked example 2. A $220 winter coat carries a 15% storewide discount, and you hold a coupon for an extra 10% off the reduced price. Step 1: the first cut is $220 × 0.15 = $33.00, leaving an intermediate price of $187.00. Step 2: the coupon applies to $187.00, not to $220 — the second cut is $187.00 × 0.10 = $18.70. Step 3: the final sale price is $187.00 − $18.70 = $168.30, and your total savings are $220.00 − $168.30 = $51.70. The combined reduction is 23.5%, not 25%: stacked percentages multiply rather than add. The general rule for two stacked discounts of a% and b% is a combined discount of a + b − (a × b ÷ 100), so 15% and 10% combine to 15 + 10 − 1.5 = 23.5%.
Example 1 — the student laptop deal. A laptop is advertised at $899 with 20% off for students. Before driving to the store, you run the numbers: the discount is $899 × 0.20 = $179.80, so the sale price is $899 − $179.80 = $719.20. At checkout, 6% sales tax applies — and here is the detail most shoppers miss: the tax is charged on the discounted price, not the original. Tax = $719.20 × 0.06 = $43.15, making your out-the-door total $762.35. Had the tax been charged on the full $899, you would have paid $10.79 more. Knowing the true total in advance also lets you compare honestly with alternatives: an online listing at $749 with free shipping and the same 6% tax costs $793.94, so the in-store student deal genuinely wins by about $31.
Example 2 — auditing an “up to 70% off” clearance rack. On a clearance rack promising “up to 70% off,” you find boots originally $160 with a red sticker price of $64. Is that really 70% off? Work it backwards: savings = $160 − $64 = $96, and $96 ÷ $160 = 0.60, so the actual percent off is 60%. The “up to” applied to other items on the rack, not these boots. Still, 60% off is a genuine bargain — you keep $96 and pay $64. The reverse formula (discount % = savings ÷ original price × 100) is worth memorizing, because it lets you audit any sale sign in seconds, and it exposes the common retail practice of advertising the deepest cut in the store as though it applied to everything.
Mistake 1 — Adding stacked percentages. “30% off plus an extra 20% off” is not 50% off. The second cut applies to the already-reduced price: on a $100 item, the first discount leaves $70, and 20% off $70 is $14, so you pay $56 — a 44% total reduction, not 50%. Retailers count on shoppers making exactly this error, because the imagined “50% off” feels more exciting than the real 44%.
Mistake 2 — Discounting the tax-included total. The discount comes off the merchandise subtotal, and sales tax is then charged on the smaller amount. If you apply the percentage to a tax-included total, you will misstate both the savings and the sale price. Work from the pre-tax price and add tax at the very end.
Mistake 3 — Confusing “percent off” with “percent of.” “30% off” a $50 shirt means you pay 70% of $50, which is $35. Shoppers in a hurry sometimes compute 30% of $50 ($15) and mistake that figure for the price rather than the savings. Before you trust a number, pause and ask: did I just calculate what I pay, or what I save?
Mistake 4 — Trusting an inflated “was” price. A 60% percent off an exaggerated original price can easily cost more than 20% off a fair one. Some retailers inflate the reference price precisely so the percentage looks heroic. Judge the final sale price against competitors and price-history trackers instead of celebrating the percentage on the sign — and use the reverse formula from the FAQ below to check whether the “was” price was ever real.
Mistake 5 — Forgetting the costs a discount does not touch. Shipping, gift wrap, assembly, and extended warranties are usually added after the markdown is applied. A 25%-off $80 item with $12 shipping costs $72 — an effective discount of only 10% once shipping is included. Add every fixed fee first, then decide whether the deal still deserves celebrating.
Percent-off math connects to several of our other free tools. The Discount Calculator handles stacked markdowns with sales tax, the Sales Tax Calculator isolates the tax portion of any checkout total, and the Tip Calculator splits restaurant bills the same way stores add tax. For any other percentage question, try the Percentage Calculator; to check the true cost of “0% financing” promotions, use the Loan Calculator; and to project what invested savings could grow into, visit the Savings Calculator.
This page defines percent-off calculation as: sale price = original price × (1 − discount/100); savings = original price × discount/100; discount percentage = savings ÷ original price × 100; original price = sale price ÷ (1 − discount/100). Stacked discounts combine multiplicatively: after discounts of a% and b%, the buyer pays (1 − a/100)(1 − b/100) of the original, so the total discount equals a + b − (a × b ÷ 100), never a + b. Sales tax applies to the discounted subtotal, not the original price. Key entities: discount (the reduction amount or rate), sale price (the amount paid after the reduction), percent off (a promotional reduction expressed as a percentage), savings (original price minus sale price).
Multiply the original price by the discount percentage written as a decimal, then subtract the result from the original price. For example, 25% off an $80 item: $80 x 0.25 = $20 discount, so the sale price is $80 – $20 = $60. The calculator at the top of this page performs the same steps instantly.
Sale price = Original price x (1 – Discount / 100), and Savings = Original price x (Discount / 100). These two formulas handle every simple percent-off deal. For stacked discounts, apply each percentage to the running subtotal in order rather than adding the percentages.
Multiply the price by 0.20 to find the discount and subtract it – or multiply the price by 0.80 to jump straight to the sale price. On a $150 item, 20% off means a $30 discount and a $120 sale price.
No. The second discount applies to the already-reduced price. On a $100 item, 30% off leaves $70, and 20% off $70 is $14, so you pay $56 – a total discount of 44%, not 50%. Stacked percentages multiply; they never add.
Divide the sale price by (1 – discount as a decimal). If you paid $84 after 30% off, the original price was $84 / 0.70 = $120. This reverse calculation is useful for checking whether a was price printed on the tag was ever genuine.
In most places the discount is applied first and sales tax is charged on the reduced price, which saves you money: 6% tax on a $70 sale price is $4.20, versus $6.00 on the original $100. Always enter the pre-tax merchandise price into the calculator above.
Percent off scales with the price – 20% off saves $40 on a $200 item but only $10 on a $50 item. A dollars-off coupon, such as $10 off, saves the same amount whatever the price, so its effective percentage shrinks as the basket grows. Compare competing offers as final sale prices, not as percentages.
Subtract the sale price from the original price to get the savings, divide by the original price, and multiply by 100. For an item reduced from $160 to $64: ($160 – $64) / $160 x 100 = 60% off.
Sources: U.S. Federal Trade Commission, Guides Against Deceptive Pricing; Khan Academy, Percent Word Problems; National Retail Federation, reporting on promotional pricing practices.
Last updated: October 8, 2026.