Compare the crossed-out price with the sale price and get the clean number: no fooling ourselves during Black Friday or the sales.
| Saving per unit | – |
| Final price per €100 of the original | – |
–
| Promotion | Real discount |
|---|---|
| 3-for-2 (pay 2, take 3) | 33.3% |
| Second item free | 50% |
| Second item at −50% | 25% |
| Second item at −70% | 35% |
| −70% + extra 20% | 76% |
| −50% + extra 10% | 55% |
If you only wanted one unit, second-item promos save you less: the table shows the average discount over the total.
Sometimes. The crossed-out price is the store's declared reference price; rules require it to have been real, but the common trick is inflating it weeks before. Your best defence: check the price history (deal trackers keep it) and other stores' prices on the "deal" day.
Because the second discount applies to what remains, not the original: €100 → −70% → €30 → −20% → €24. Total: −76%. Stacked percentages don't add up: they compose.
Order doesn't matter: −20% then −70% gives the same final 76%. What changes everything is the base: a coupon on the already-discounted price saves far fewer euros than on the original, even if the percentage looks the same.
Three signs: a crossed-out price that only appears days before the campaign, a "deal" price equal to or above other stores' everyday price, and second-item promos when you only need one. With this calculator you'll at least see the real percentage, clean.
Real discount: (old − current) ÷ old × 100. Stacked: 1 − (1 − p₁) × (1 − p₂). Pure arithmetic: we don't look up prices and we store nothing of what you type. Works for Black Friday, January sales, Prime Day and any banner-with-a-percentage campaign.
We are not a price-history tracker: to verify a crossed-out price, use a deal tracker or the competition. Orientative; see terms of use.