What is the Discount Calculator?
Working out a sale price is straightforward arithmetic that shops rely on customers getting slightly wrong. The single most useful habit is checking the actual amount saved rather than responding to the size of the percentage.
This calculator gives the final price after a discount and the amount saved, so you can see both figures rather than just the headline reduction.
What each input means
- Original price
- The price before discount. Be sure this is the genuine selling price, not an inflated reference price.
- Discount
- The reduction as a percentage.
- Second discount
- An extra percentage off for stacked offers. It applies to the price after the first discount, so 20% and then 10% comes to 28% off, not 30%.
- Tax added afterwards
- Sales tax charged on the discounted price, for shops that show prices before tax. Leave it at 0 when the price already includes tax.
How this calculation works
The final price is the original multiplied by one minus the discount as a decimal. Thirty percent off 2,000 leaves 2,000 × 0.7, which is 1,400, with 600 saved.
Successive discounts behave differently from what the labels suggest. An extra ten percent off an already reduced price applies to the reduced figure, not the original, so twenty percent followed by ten percent is twenty-eight percent in total rather than thirty.
Formula: Result = the relevant inputs combined using the displayed assumptions.
Getting the most out of the result
- Look at the amount saved, not the percentage. Half off something you do not need saves nothing.
- Check whether the reference price is real. Inflated "was" prices make ordinary prices look like bargains.
- Multiply successive discounts rather than adding them.
- Confirm whether tax is applied before or after the discount, as it changes the final figure.
- Compare the discounted price against other retailers rather than against the claimed original.
Common mistakes to avoid
Shoppers routinely add stacked discounts together and expect a larger reduction than they receive, since each applies to a progressively smaller base. Judging a deal by percentage rather than absolute saving is the more expensive habit, since a large percentage off an unnecessary purchase still costs money. Inflated reference prices are widely used and rarely questioned. And working backwards from a sale price to the original by adding the percentage back gives the wrong answer — that requires division.
Frequently asked questions
How do I calculate a discount quickly?
Multiply the price by the discount as a decimal to find the saving, or by one minus that decimal to find the final price. For 25 percent off, multiply by 0.75 to get what you pay.
How do stacked discounts work?
They multiply. Thirty percent off followed by twenty percent off the reduced price gives 0.7 × 0.8 = 0.56, so you pay 56 percent of the original — a 44 percent total discount, not 50.
How do I find the original price from a sale price?
Divide the sale price by one minus the discount. If 30 percent off gives 1,400, the original was 1,400 ÷ 0.7 = 2,000. Adding 30 percent back to 1,400 gives the wrong answer.
Is tax applied before or after the discount?
Usually after, on the actual amount paid, but practice varies by jurisdiction and retailer. It changes the final figure, so check the receipt if the total looks unexpected.
What is a reference or "was" price?
The higher price a retailer claims an item previously sold at. Consumer rules in many places require it to have been genuinely charged for a period, though enforcement varies. Compare against other sellers rather than trusting it.
Which is better, a percentage off or a fixed amount off?
Compare the actual saving. A fixed reduction beats a percentage on cheaper items and loses on expensive ones. Work out both in currency terms rather than comparing the labels.
Does a bigger discount mean a better deal?
Not necessarily. The relevant questions are what you pay compared with elsewhere, and whether you needed the item. A large discount from an inflated starting price is not a saving at all.