How discounts are calculated
A percentage discount reduces a price by that proportion of the original. Twenty-five percent off two thousand removes five hundred, leaving fifteen hundred. The arithmetic is simple, but two situations trip people up reliably.
Stacked discounts do not add up
This is the one worth internalising. A "30% off, then an extra 20% off" offer is not 50% off. The second discount applies to the already-reduced price, not the original.
Starting at 100: thirty percent off gives 70, and twenty percent off 70 gives 56. That is 44 percent off in total, not 50. The gap widens as the individual discounts grow, and retailers are well aware of how the phrasing reads.
The calculator above shows the true effective rate whenever you enter a second discount, precisely because the intuitive answer is wrong.
Working backwards
The second calculator answers the more useful question when you are shopping: given an original price and a sale price, what discount is that actually? This is worth checking because advertised percentages and actual shelf prices sometimes disagree, and because "was" prices are not always what the item genuinely sold for.
Discount versus markup
These are not symmetrical, which causes real confusion in retail. A price marked up by 50 percent requires a discount of 33 percent to return to the original, not 50. The reason is that the two percentages are calculated against different bases — the markup against the lower figure, the discount against the higher one.
The same asymmetry means a 50 percent discount requires a 100 percent increase to reverse.
Reading sale pricing critically
A few things are worth knowing. "Up to 70% off" means at least one item somewhere carries that discount; most will be far lower. Reference prices in many jurisdictions must reflect a price the item genuinely sold at for a defined period, but enforcement varies considerably.
The most useful habit is to judge the final price against what the item is worth to you, rather than against the claimed saving. A large discount on something overpriced is still overpriced, and discount framing is effective precisely because it shifts attention from the price paid to the money supposedly saved.
Calculated locally
All arithmetic happens in your browser. Nothing is transmitted, and no figures are stored.
Frequently Asked Questions
Is 30% off then 20% off the same as 50% off?
No. It works out to 44 percent off, because the second discount applies to the already-reduced price rather than the original.
How do I find the discount percentage from two prices?
Subtract the sale price from the original, divide by the original, and multiply by 100. The second calculator above does this.
Why does a 50% markup need only a 33% discount to reverse?
Because the two percentages are measured against different bases — the markup against the lower price, the discount against the higher one.
Does this include tax?
No. It calculates the discount on the price you enter. Whether tax applies before or after the discount depends on your jurisdiction.
What does "up to 70% off" mean?
That at least one item carries that discount. Most items in such a sale are discounted considerably less.