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Black Friday falls on November 27, 2026 this year, the day after US Thanksgiving, and Cyber Monday on November 30, 2026. The quickest test of any deal: work out the price you will actually pay and compare it with what the item normally sells for – not with the percentage on the banner. A “30% off, plus an extra 20%” offer is 44% off, not 50%.
This guide walks through the five checks that catch most weak deals, with every figure worked out in our discount calculator and related tools.
1. Stacked discounts are smaller than they look
When a shop offers an extra discount “on sale prices”, the second percentage is taken off the already-reduced price, not off the original. Multiply the remaining shares together instead of adding the percentages.
Take a USD 200.00 coat at 30% off: it drops to USD 140.00. An extra 20% off that brings it to USD 112.00. You save USD 88.00, which is 44% of the original price. Swapping the order – 20% first, then 30% – gives the same USD 112.00.
| Offer | You pay on $100 | Real discount | What adding suggests |
|---|---|---|---|
| 20% off, then an extra 10% off | USD 72.00 | 28% | 30% |
| 25% off, then an extra 10% off | USD 67.50 | 32.5% | 35% |
| 30% off, then an extra 20% off | USD 56.00 | 44% | 50% |
| 40% off, then an extra 20% off | USD 48.00 | 52% | 60% |
| 50% off, then an extra 20% off | USD 40.00 | 60% | 70% |
| 50% off, then an extra 50% off | USD 25.00 | 75% | 100% |
The gap grows with the size of the discounts. “Half price, then an extra half off” sounds free but leaves you paying a quarter of the price.
2. Check the “was” price, not the percentage
A discount is only as real as the price it starts from. Suppose a speaker shows “was USD 120.00, now 25% off” at USD 90.00. If it sold for USD 90.00 for most of the autumn, your real saving against that price is 0% – nothing at all. If its usual price was USD 100.00, the real saving is 10%, not 25%. Our percentage change calculator gives that figure from any two prices.
Rules on reference prices differ by region:
- United States: the Federal Trade Commission’s Guides Against Deceptive Pricing say a former price is a fair comparison only if the item was genuinely offered at that price, openly and in good faith, for a reasonably substantial period. They are guidance, so treat any “was” price as a claim to verify.
- European Union: since the 2019 amendment of the Price Indication Directive, a shop announcing a price reduction must show the prior price, defined as the lowest price it charged in at least the 30 days before the reduction. Member states may allow exceptions, for example for perishable goods.
To work backwards from a sale tag, divide by 1 minus the discount: a USD 63.00 item marked 30% off was USD 90.00.
3. Turn multi-buy offers into a percentage
Bundles are easier to compare once they are a single percentage. “Buy one, get one half price” on two USD 40.00 items means paying USD 60.00 instead of USD 80.00 – a 25% discount, and only if you wanted both. For different pack sizes, compare the price per unit with our unit price calculator.
4. Add tax where the shelf price leaves it out
In the US, sales tax is added at the till on the discounted price. The USD 112.00 coat in Texas at the 6.25% state rate costs USD 119.00, including USD 7.00 of tax. Local taxes can add more; enter your combined rate in the sales tax calculator.
In the UK, the EU and the Gulf, the price on the tag already includes VAT, so the discount applies to the full price you pay. A GBP 250 UK item at 30% off costs GBP 175.00, of which GBP 29.17 is VAT at 20%. In Saudi Arabia, a SAR 1,150 item at 30% off costs SAR 805.00, including SAR 105.00 VAT at 15%. Businesses that reclaim VAT can split any receipt with the VAT calculator.
5. Count the interest if you pay by card
A discount bought on a credit card you do not clear in full can cost more than it saves. A USD 1,000.00 Black Friday balance at 22% APR, paid off at USD 50.00 a month, takes 26 months and adds USD 257.13 of interest. Paying USD 100.00 a month clears it in 12 months with USD 114.90 of interest. Try your own balance in the credit card payoff calculator.
Black Friday checklist
- Write down the usual price of anything you plan to buy now, before November 26, 2026, so you can compare it with the Black Friday price.
- Work out the final price – after every discount and before shipping – and compare that, not the percentage.
- Multiply stacked discounts; never add them.
- Add sales tax and delivery costs where they are charged on top.
- Check the returns window: some sale items have shorter return periods.
- If you will not clear the card at the next statement, add the interest to the price.
How we calculated this
Every amount comes from our calculators’ own code: discounts rounded to the cent after each step, as at a till; US sales tax at the Texas state rate only; VAT at 20% (UK) and 15% (Saudi Arabia), removed from a VAT-inclusive price; and card interest charged monthly at the APR ÷ 12 on the remaining balance, with no new purchases or fees. Dates follow the US rule that Thanksgiving is the fourth Thursday of November.
Sources
- FTC Guides Against Deceptive Pricing, 16 CFR Part 233 – ecfr.gov
- Directive (EU) 2019/2161, amending Directive 98/6/EC (Article 6a, prior price) – eur-lex.europa.eu
General information, not tax advice or financial advice. Prices, promotions and tax rules vary by shop and location.