Discount Calculator

How it works

A percentage discount reduces the original price by a given proportion. Knowing the exact saving helps you compare deals and decide whether a sale price is genuinely good value.

The formula

You can also calculate the sale price directly with: Sale Price = Original Price x (1 - Discount % / 100). Both methods give the same result.

Why this works: The discount percentage represents the fraction of the original price being removed. Multiplying by (1 - discount) gives you the remaining fraction you actually pay. A 30% discount means you keep 70% of the original price, so multiplying by 0.70 gives the sale price in a single step, making it easy to check deals in shops or online.

Related calculations

Use this calculator when shopping in sales, applying promotional codes, or checking trade discounts. If there is also VAT to consider, you can add VAT to the net price after the discount. To express how much a price has fallen as a rate, you can find the rate at which a price has fallen. For splitting a restaurant bill with a service charge, the bill splitter with tip handles that calculation.

The psychology of discounts

Retailers use several psychological tactics that make discounts feel more compelling than they may actually be. Understanding them helps you decide whether a deal is genuinely good value.

Anchoring: When a retailer shows a high original price next to a lower sale price, the original price acts as an anchor. You judge the deal by how far below the anchor the sale price falls, not by whether the anchor price was ever realistic. Some retailers inflate the "was" price before a sale so the discount appears larger. In the UK, the Advertising Standards Authority requires that a product must have been sold at the higher price for a meaningful period before it can be used as a reference in a sale.

The charm of round percentages: "50% off" and "25% off" feel decisive and significant. "23% off" feels underwhelming even if the absolute saving is larger. This is why sale banners almost always use clean round percentages, regardless of the true saving.

Spotting genuine value: The quickest check is to calculate the sale price and ask whether you would buy this item at that price if you had never seen the "original" price. If the answer is yes, it may well be a good deal. If the answer is no, the discount has done its psychological job regardless of whether the saving is real.

Worked examples

When to use this

This calculator is most useful in four situations:

• Sales shopping: During Black Friday, January sales, or summer clearance, retailers advertise a percentage off across entire product ranges. Quickly checking the final price before you buy avoids confusion at the till and helps you compare two items at different original prices and discount rates.
• Promotional codes: Online retailers frequently offer percentage-off codes (e.g. 15% off your first order). Entering the original basket value and discount percentage tells you exactly how much you save before checkout.
• Trade discounts: Many UK trade suppliers offer tiered percentage discounts based on order volume. A 10% trade discount on a £4,000 order saves £400; a 20% discount saves £800. Comparing these in advance helps you decide whether it is worth ordering more to hit a higher discount tier.
• Insurance and subscriptions: Introductory offers often advertise "50% off for the first six months." Knowing the discounted monthly cost and the full-price cost after the offer ends helps you decide whether the long-term price is acceptable.

Understanding the result

The calculator gives you two figures: the saving (what you do not pay) and the sale price (what you do pay). A 50% discount halves the price. A 75% discount leaves you paying one quarter. A 100% discount would mean the item is free. Discounts above 100% are not possible, as you cannot pay less than nothing.

Keep in mind that stacked discounts do not add up linearly. A 20% discount followed by an additional 10% discount gives a combined saving of 28%, not 30%, because the second discount applies to the already-reduced price.

Related concepts

➡ If a price tag shows a "% off" label and you need the final amount quickly, the percentage off calculator is optimised specifically for that format. ➡ To check the pre-sale original price from a discounted figure and a percentage, you can reverse the calculation to recover the full price before the promotion. ➡ To find what price an item was before a sale, given the sale price and the percentage off, the reverse percentage finder works backwards from the discounted amount to the original.

How to do this in Excel

Put the original price in A1 and the discount percentage in B1. This formula calculates the sale price directly. To find the saving separately, use =A1*B1/100. Both can sit in adjacent cells so you see saving and final price at a glance.

How to do this without a calculator

Find 10% of the original price by moving the decimal one place left. Multiply that by the discount percentage in units of 10 (e.g. 30% is three lots of 10%). For a 25% discount, halve the 10% figure to get 5%, then add to the 20% figure. For example, 25% off £80: 10% = £8, 20% = £16, 5% = £4, so 25% = £20 saving, leaving £60 to pay.

Real world uses

• Finding the sale price of clothing marked down in a Black Friday or January sale.
• Calculating the saving on a sofa or white goods after a seasonal percentage discount.
• Checking how much you save when a supermarket applies a multipack discount.
• Working out the final price of a laptop or phone after a student or loyalty discount.
• Comparing two retailers where each offers a different percentage off the same item.

Common mistakes

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