Discount Calculator: Sale Price, % Off & BOGO

Calculate sale price with stacked % and fixed coupons, tax and quantity; find the discount % or original price; value buy-one-get-one deals; and compare up to 8 deals by unit price.

Built and maintained by Shehzad Munir ·

Discount Calculator
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Know the real price before you buy

Enter a price and any number of discounts to see the final price and the real combined discount. Work backwards from a sale price, check what a 'buy 2 get 1 free' deal is worth, or compare pack sizes to find the cheapest per gram or litre.

Sale tags show a percentage off, but the number that matters is what you actually pay. Enter the original price and the discount and this calculator shows the final price and your savings instantly. Add a second coupon to model 'extra 10% off sale items', and include sales tax to see the true checkout total.

Features

  • Stacked discounts: % and fixed amounts in order
  • Sales tax on the discounted or original price
  • Quantity totals and a discount table
  • Find % off from original and sale price
  • Find the original price before a discount
  • BOGO and buy X get Y at Z% off
  • Compare deals by unit price with a winner badge

How to use Discount Calculator

  1. 1

    Choose a mode

    Sale price, % off, Original price, BOGO or Compare.

  2. 2

    Enter prices and discounts

    Add coupons in the order the store applies them.

  3. 3

    Add tax and quantity

    See the final price per item and in total.

  4. 4

    Compare deals

    Enter price, discount and size for each option to find the best value.

Common use cases

  • Find the sale price of a discounted item
  • Check savings from stacked coupons
  • Add sales tax to see the checkout total
  • Compare two competing deals

Detailed guide

Handy for shoppers and sellers

Shoppers can compare deals and check whether a coupon is worth it; sellers can price promotions and confirm margins still hold. The quick-percent buttons make common discounts one tap away. Everything is calculated in your browser, nothing is uploaded.

Stacked discounts don't add up

Two discounts applied one after the other are always worth less than their sum. A 20% sale followed by a 10% coupon on a $100 item gives $100 × 0.80 × 0.90 = $72, a 28% saving, not 30%. The order doesn't change the result: multiplying by 0.90 then 0.80 gives the same $72. What does change the result is whether a coupon is a percentage or a fixed amount, and whether it applies before or after the sale price. A $10-off coupon is worth more on a cheaper item, while a percentage coupon is worth more on an expensive one.

Tax, original prices and working backwards

In most US states sales tax is charged on the discounted price, while VAT-inclusive prices in the UK and EU already include tax, so check which applies before comparing deals. To find the original price from a sale price, divide by one minus the discount: a $45 item marked 25% off was $45 / 0.75 = $60. Be wary of "was" prices that were never actually charged; comparing the final price with other shops is more reliable than trusting the size of the percentage. For sellers, the calculator shows how much margin a promotion gives away before you run it.

Frequently asked questions

Do two 20% off coupons make 40% off?

No. The second coupon applies to the already-reduced price, so 20% + 20% = 36% off. The calculator shows the true combined discount.

How do I find the original price from the sale price?

Divide the sale price by (1 − discount ÷ 100). A 75 item at 25% off was 75 ÷ 0.75 = 100.

How do I calculate a percentage discount?

Multiply the price by the discount percentage to get the savings, then subtract it from the price. This tool does it instantly and also shows the final total.

Can it handle two discounts?

Yes. Enter a second coupon and it's applied on top of the first (stacked), just like 'extra 10% off sale prices'.

Does it include sales tax?

Optionally. Add a tax percentage and the calculator adds it to the discounted price for the true checkout total.

Is my data stored?

No. All calculations run locally in your browser and nothing is uploaded.

How do I calculate the sale price after a percentage off?

Sale price = original price x (1 - percent/100). A 30% discount on $120 is $120 x 0.70 = $84, a saving of $36. Enter the price and discount to see both the final price and the amount saved.

How do I find the original price from a sale price?

Original = sale price / (1 - percent/100). If an item is $84 after 30% off, the original was 84 / 0.70 = $120. Use the reverse mode to work it out.

How do I calculate a double or stacked discount?

Apply each discount in turn, not by adding them. 20% then 10% off $100 is $100 x 0.80 x 0.90 = $72 (a 28% total discount, not 30%). The calculator chains discounts correctly.

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