Everyday money
Discount Calculator
Work out the sale price and exactly how much you save from a percentage off, stack two discounts to see the real combined rate, or run it in reverse to find the original price from a sale tag. This is the math behind Black Friday doorbusters, "take an extra 20% off clearance" coupons, and the percentage-off codes you paste at checkout — and stacked deals rarely save as much as the headline rates suggest. Pick a mode, type your numbers, and the worksheet updates instantly in your browser so you can decide whether a deal is really worth it.
Discount details
Enter a price and discount
Stacked discounts apply one after another, so two 50% offs are not 100% off.
How the discount calculator works
A percentage discount multiplies the price by the fraction that remains after the cut. The three modes share the same idea: a single discount keeps (1 − rate) of the price; a stacked discount applies the second cut to what is left after the first; and reverse mode divides the final price by the remaining fraction to recover the original.
Active formula
salePrice = price × (1 − discount ÷ 100)where: price = original price before the discount discount = percentage off amount saved = price − salePrice
The three modes
- Single discount — original price minus one percentage off.
- Stacked discount — apply the second percentage to the price left after the first; the effective rate is always less than the two added together.
- Reverse — given the final (sale) price and the percentage off, recover the original price with original = final ÷ (1 − discount ÷ 100).
Notes & assumptions
- Discounts are capped at 0–100%; a 100% reverse discount is invalid because it would divide by zero.
- Taxes, shipping and coupon minimums are not included.
- Calculations are for general information only — verify at checkout before relying on them.
Worked example: a jacket with a stacked coupon
A jacket lists at $89.99 with a 30% markdown, and you have an extra 15% coupon that works on sale items. The first cut keeps 70% of the price: $89.99 × 0.70 = $62.99. The coupon then applies to that remainder, keeping 85% of it: $62.99 × 0.85 = $53.54. You pay $53.54 and save $36.45, an effective discount of 40.5%, not the 45% you would get by adding 30 and 15.
Reverse mode lets you audit a receipt. You paid $53.54 at an effective 40.5% off, so the original is $53.54 ÷ 0.595 = $89.98, matching the list price within a cent of rounding. If a reverse check lands far from the advertised original, the tag deserves a closer look.
Why stacked discounts are smaller than they look
Each additional percentage applies to what is left after the previous cut, so the combined rate always lands below the simple sum. Multiply the remaining fractions to get the truth: 20% then 10% keeps 0.80 × 0.90 = 0.72 of the price, which is 28% off, not 30%.
| First discount | Extra discount | Sounds like | Effective rate |
|---|---|---|---|
| 20% | 10% | 30% off | 28% off |
| 25% | 10% | 35% off | 32.5% off |
| 30% | 15% | 45% off | 40.5% off |
| 40% | 20% | 60% off | 52% off |
| 50% | 20% | 70% off | 60% off |
| 50% | 50% | 100% off | 75% off |
| 70% | 30% | 100% off | 79% off |
The gap widens as the percentages grow. A \"70% off clearance, extra 30% at the register\" promotion is 79% off: generous, but a full 21 points short of free. The stacked mode above computes the effective rate for any pair you type.
$10 off or 10% off: which coupon wins
Divide the dollar amount by the percentage written as a decimal to find the break-even price. $10 ÷ 0.10 = $100, so a $10-off coupon beats 10% off on anything cheaper than $100, they tie at exactly $100, and the percentage wins above it. The same rule says $15 off beats 20% off below $75, and a flat $5 beats 25% off under $20.
Retailers pick the framing that sounds bigger. On a $40 video game, \"$10 off\" and \"25% off\" are the same deal, but a 15% code on that game saves only $6. When a checkout offers a choice of codes, run each through the single-discount mode above and keep whichever leaves the lower \"you pay\" line.
Sanity-checking the \"original\" price
A percentage is only as honest as the price it is measured against, and many sale tags anchor to a list price the item rarely sold for. If a $79.99 deal claims 60% off, reverse mode says the implied original is $199.98. When every other store lists the same item around $110, the real discount against the market is about 27%, not 60%.
Three quick checks before trusting a tag: search the model number to see what other retailers charge today, look at a price-history tracker to see whether the \"sale\" price is just the everyday price, and be skeptical of items that have sat \"on sale\" continuously for months. A deal is what you pay versus what the item actually trades for, not versus the number above the strikethrough.
Frequently asked questions
How do I calculate a percentage discount?
Multiply the original price by the discount rate to get the dollars you save, then subtract that from the price for the sale price. A faster way is to multiply the price by the fraction that remains: a 25% discount keeps 75%, so $120 × 0.75 = $90. The single-discount mode above does this automatically and shows both the amount saved and the price you pay.
Do two stacked discounts add together?
No — stacked discounts are applied one after another, not summed. Taking 50% off and then an extra 50% off does not equal 100% off; the second cut applies only to what's left after the first, giving an effective discount of 75%. The stacked mode above shows the real combined rate, which is always less than simply adding the two percentages.
How do I find the original price from a sale price?
Divide the price you paid by the fraction that remained after the discount. If you paid $90 after 25% off, the remaining fraction is 0.75, so the original price was 90 ÷ 0.75 = $120. The reverse mode above does this for you and also shows how much you saved versus the original ticket price.
Is the discount applied before or after sales tax?
In the U.S., percentage discounts and coupon codes are almost always applied to the item price first, and sales tax is then calculated on the lower, discounted amount. That means a discount saves you a little on tax too. This calculator focuses on the item price and does not add sales tax — use a separate sales tax calculator for the final out-the-door total.
What does "50% off" really save me?
A 50% discount cuts the price in half, so on a $120 item you save $60 and pay $60. The savings scale directly with the original price: the same 50% saves $25 on a $50 item and $150 on a $300 item. Watch for stacked or "extra % off" promotions, where the headline numbers overstate the true combined discount.
Which is better, $10 off or 10% off?
Divide the dollar amount by the percentage to find the break-even price: $10 ÷ 0.10 = $100. Below $100 the flat $10 saves more, above $100 the percentage saves more, and at exactly $100 they match. The same test works for any pair, so $15 off beats 20% off on anything under $75.