A big red “50% off” sticker feels like a reason to buy, but it only saves you money if the original price was ever real. Plenty of sale prices are anchored to a “was” figure the item barely sold at, or never sold at, which makes the discount look far larger than it is. Spotting a fake discount comes down to a few quick checks: question the reference price, compare on unit price rather than pack size, and reverse the maths to see what the claimed saving actually implies. This guide walks through each one so you can tell a genuine deal from clever signage. To check any real reduction quickly, the CalcRange Discount Calculator gives you the final price and the amount saved.
Why Fake Discounts Work on Us
A discount is judged against the first number you see, not against what the item is worth. That first number is the anchor.
Show someone a jacket at 60 and they weigh it on its own merits. Show them the same jacket “reduced from 120 to 60” and it suddenly feels like a bargain, even though the price they pay is identical. Retailers know this, which is why the crossed-out price is often larger and bolder than the price you actually pay. The saving is doing the selling. None of this is illegal on its own, and a genuine sale uses the same layout. The problem is only when the higher number was never a real, honest price, and that is what the rest of these checks are for.
Question the “Was” Price
The whole discount rests on the reference price, so that is the number to be suspicious of first.
Ask yourself a simple question: did this item genuinely sell at the “was” price for a meaningful stretch of time, or was it marked up briefly so it could be marked down? A few warning signs suggest the latter. The “was” price is a suspiciously round number well above similar products. The item has been “on sale” every time you have ever looked. Or the reduction appears the moment a big shopping event starts and vanishes when it ends. Price-history tools and browser extensions exist for exactly this on large online retailers, and they often show that a “Black Friday” price matched the item’s ordinary price a fortnight earlier. If you can find what the thing normally costs elsewhere, you have a real anchor to judge against instead of the shop’s chosen one.
Reverse the Maths
You can test whether a claimed discount is even internally consistent with a single division.
If a sign says “30% off” and the sale price is 70, then the implied original was 70 ÷ 0.70 = 100. Now ask whether 100 is a believable everyday price for this item. If the same product sits at 75 in three other shops, an implied “original” of 100 tells you the discount is measured from a fiction. The general rule is that the sale price equals the original times (1 minus the discount), so to recover the original you divide the sale price by (1 minus the discount as a decimal). Our full guide to calculating discounts and sale prices covers this reverse calculation and stacked offers in detail. The point here is narrower: a claimed percentage plus a sale price gives you an implied original, and if that implied original looks absurd, the deal is theatre.
Check a Real Discount
When a reduction is genuine and you just want the numbers, drop the original price and the percentage into the CalcRange Discount Calculator to see the final price and exactly what you save. For a claimed saving you want to sanity-check, the percentage calculator handles the reverse step.
Compare on Unit Price, Not Pack Size
The “bigger pack is better value” assumption is wrong often enough to be worth checking every time, because a lot of fake savings hide in pack size.
Say a 500 g jar costs 3.00, so 0.60 per 100 g. The “family size” 750 g jar next to it costs 4.80, which works out at 0.64 per 100 g. The bigger jar is dearer per gram, despite looking like the value option. Supermarkets in many countries are required to print the unit price (per 100 g, per litre, per item) on the shelf label precisely so you can compare, and it is usually in small text under the headline price. Get into the habit of reading that small number instead of the big one. “Buy one get one free,” “3 for 2,” and multi-buys are the same story: they can be real savings or a nudge to buy more than you need, and only the per-unit price tells you which.
Other Tricks to Watch For
- “Up to 70% off” almost always means a handful of items are at 70% and most are at 10%. The phrase “up to” is the tell.
- Countdown timers and “only 2 left” banners manufacture urgency so you buy before you check. A real deal is still a deal after five minutes of comparison.
- Shrinkflation dressed as a saving: the price held steady but the pack got smaller, so the unit price rose while the sticker looked unchanged.
- Drip pricing, where a low headline price grows with fees added at checkout. Judge the total you actually pay, not the first figure shown.
- “Free gift with purchase” that quietly requires you to spend more than you meant to, wiping out any saving on the thing you came for.
The Rules That Are Meant to Protect You
Consumer law in several regions has caught up with reference-price games, though enforcement and detail vary by country.
In the European Union, the Omnibus Directive, which member states applied from 28 May 2022, requires that when a trader announces a price reduction, they must display the lowest price the item was sold at during at least the previous 30 days. That stops the mark-up-then-mark-down trick, at least on paper. The United Kingdom has moved against drip pricing and misleading practices through the Digital Markets, Competition and Consumers Act 2024, and its trading-standards pricing guidance addresses reference pricing. These rules help, but they do not make every “sale” honest, and they differ from place to place. Your own checks remain the reliable defence, because a rule you have to enforce after the fact is weaker than a comparison you make before you buy.
Frequently Asked Questions
How can I tell if a discount is fake?
Question the “was” price first: check whether the item genuinely sold at that figure recently, or compare it to the price in other shops. Then reverse the maths, dividing the sale price by one minus the discount to see the implied original. If that implied original looks unrealistic, the saving is measured from an inflated reference rather than a real one.
What is anchor pricing?
Anchoring is the tendency to judge a price against the first number you see rather than the item’s actual value. A crossed-out higher price makes the price you pay feel like a bargain, even when it is unchanged. Retailers use a bold reference price to make the discount, not the product, do the selling.
How do I work out the original price from a sale price?
Divide the sale price by one minus the discount written as a decimal. A 30% reduction to a sale price of 70 implies an original of 70 divided by 0.70, which is 100. This lets you check whether the claimed original is believable against what the item costs elsewhere.
Is a bigger pack always cheaper?
No. Larger packs are often, but not always, better value, and sometimes the family size costs more per unit than the standard size. Compare the unit price, the per 100 g or per litre figure on the shelf label, rather than the headline price or the pack size. That small number is the honest comparison.
What does “up to 70% off” really mean?
It usually means only a few items are reduced by the full amount, while most carry a much smaller discount. The words “up to” set the ceiling, not the typical saving. Treat the headline as the best possible case and check the actual reduction on the specific item you want.
Are shops allowed to inflate a price before a sale?
It depends on the country. In the European Union, since May 2022 traders announcing a reduction must show the lowest price from at least the previous 30 days, which curbs the trick. Other regions have their own rules with varying strength and enforcement. Where protections are weak, your own price comparison is the reliable safeguard.
Do price-history tools actually help?
Yes, for large online retailers. Browser extensions and price-tracking sites chart what an item has cost over time, so you can see whether a “sale” price is genuinely low or just matches the usual price. They will not cover every shop, but for major stores they turn a guess into a check.
The Bottom Line
A discount is only real if the original price was real, so treat the crossed-out figure as a claim to test, not a fact. Check whether the item truly sold at that price recently, reverse the maths to see the implied original, and compare on unit price rather than pack size. Ignore manufactured urgency and read the total you actually pay. When a reduction is genuine, the discount calculator gives you the real saving in seconds, and a little scepticism at the shelf does the rest.
Last reviewed: August 2026. Recommended editorial review: every 12 months, since consumer pricing rules change by country and over time. Legal details here are general and not a substitute for local consumer-protection guidance.