Black Friday Deal Calculator

Black Friday is Friday, November 27, 2026, and Cyber Monday follows on Monday, November 30, and Adobe expects $275.1 billion of online holiday spending between November 1 and December 31, which is 6.7 percent more than last season, and the discounts climb through the season, from up to 14 percent off at the start of November to up to 30 percent during Cyber Week, and the banners will say 40 percent and 50 percent and 70 percent, and the banners lie by arithmetic, not by intent, because 30 percent off plus an extra 20 percent off is 44 percent off, not 50, and a TV listed at $899 and sold at $749 is 16.7 percent off, whatever the banner says, and a deal is only real when the sale price is below the lowest price the item sold for in recent weeks. This ledger checks the deal three ways: the claimed discount against the was price, the real saving against the recent lowest price, and the stacked discounts the honest way, and then it prices what the card adds, because a discount bought on a card you do not clear in full can cost more than it saves.

Sources: Adobe holiday forecast, published September 28, 2026 ($275.1 billion online November 1 to December 31, up 6.7 percent; discount ramp and category peaks); National Retail Federation 2025 holiday spending survey ($890.49 planned per person, about $628 on gifts); Deloitte 2025 holiday survey ($1,595 average planned budget, down 10 percent from 2024); 2025 online totals of $11.8 billion on Black Friday and $14.25 billion on Cyber Monday. The card-interest figures are this calculator’s own amortization at the stated APR and monthly payment. This is arithmetic, not a list of deals: it does not judge whether a retailer broke the law, and it does not track live prices. Write down the usual price of anything you plan to buy now, before November 26, so you can compare it with the Black Friday price.

Black Friday is in 20 days. Cyber Monday is Monday, November 30, 2026.

Step 1 — Is the deal real?

The was price is the claim. The lowest recent price is the evidence. A discount is only as real as the price it starts from: if the item sold for $140 for most of the autumn, a $112 sale price saves $28 against that price, which is 20 percent, not the 44 percent the tag claims, because the tag measures from a was price the item may rarely have sold at. The Federal Trade Commission’s Guides Against Deceptive Pricing set the rule for a crossed-out price: the was price must be a genuine former price, not a number invented for the sale.

The ledger

REAL DEAL

Was $200.00, sale $112.00, recent lowest $140.00: the claimed discount is 44.0 percent, the real saving is 20.0 percent, and the tag overstates the saving by 24.0 points, because the claimed discount is measured from the was price and the real saving is measured from the lowest price the item actually sold for.

Step 2 — Stack the discounts honestly

Two percentage discounts multiply, they do not add. A 30 percent sale plus an extra 20 percent coupon leaves you paying 70 percent of 80 percent of the price, which is 56 percent, so the real discount is 44 percent, and on a $200 item that is $112, not $100. A fixed-value coupon is different: apply the percentages first and a $20 coupon off a $120 item after 30 percent off leaves $64, because $120 times 0.70 is $84, minus $20 is $64. Apply the coupon first and the same $20 is worth less, because the percentage then takes a cut of it: $120 minus $20 is $100, times 0.70 is $70.

$112.00 final price after the stack

Real saving: $88.00 (44.0%) · headline sum of the discounts: 50% · the headline overstates it by 6.0 points

After 30% off: $140.00. After a further 20% off: $112.00. No coupon. The three discounts are not 50% off; they are 44.0% off, because each percentage is taken from the price that is left.

Step 3 — What the card adds

A discount bought on a credit card you do not clear in full can cost more than it saves. A $1,000 Black Friday balance at 22 percent APR, paid off at $50 a month, takes 26 months and adds $257.14 of interest. Paying $100 a month clears it in 12 months with $114.89 of interest. The interest is the deal’s real price when the card carries the balance, and the saving on the item is the number to compare it with.

26 months to clear the balance

Total paid: $1,257.14 · interest: $257.14 · the interest is $169.14 more than the $88.00 you saved on the deals

Common stacks, on a $200 item

The headline sum is what the banner adds. The real saving is what the till charges. The gap between them grows with every discount you stack, because each percentage is taken from a smaller price, and the smaller the price, the smaller the saving each new percentage buys.

The table is the same function this calculator uses, run on a $200 item. The last row is the proof: 50 percent off plus an extra 50 percent off is not free, it is $50.00, because the second 50 percent is taken from the $100 that is left, not from the $200 you started with. Small jumps in the discount hide bigger jumps in the price: moving from 20 percent off to 30 percent off sounds like a 10 percent drop, but the price falls from 80 percent of list to 70 percent, which is a 12.5 percent drop, and the drop is the number that matters, because the price is the money.

The number to carry out of this page is the real saving against the lowest price you have seen, because the claimed discount is the banner and the real saving is the till, and the stack is the second number, because the stack is where the banner’s arithmetic hides, and the card is the third, because the interest is where the saving goes to die, and the three together are the deal, and the deal is real only when the sale price is below the recent lowest, the stack is priced honestly, and the card is cleared in full.