Percentage Discount Calculator

Enter the original price and discount percentage to find the amount you save and the sale price, with optional support for a second stacked discount and sales tax.

Quick Facts

Formula
Sale Price = Price x (1 - Discount% / 100)
The discount amount is the original price multiplied by the discount rate.
Stacked discounts
Multiply, don't add
A 20% discount then an extra 10% off saves 28% total (0.8 x 0.9 = 0.72), not 30%, since the second discount applies to the already-reduced price.

Your Results

Calculated
You Save
-
Total discount amount
Sale Price
-
Price after all discounts, before tax
Effective Discount
-
Combined percentage off the original price
Final Price
-
Sale price plus sales tax, if any

Ready

Enter the original price and discount percentage, then press Calculate.

How the Percentage Discount Calculator works

This tool answers the everyday shopping question: if an item is marked down by a given percentage, how much do you actually save, and what do you pay? It uses the standard percentage-discount formula, with optional support for a second stacked discount (coupon on top of a sale) and sales tax applied afterward.

The formula

For an original price P and a discount rate d (as a percent), the amount saved and the sale price are:

Discount Amount = P x (d / 100)
Sale Price = P - Discount Amount = P x (1 - d / 100)

If a second discount is applied on top of the first — a loyalty coupon stacked on a storewide sale, for example — it is calculated on the already-discounted price, not the original price: Sale Price = P x (1 - d1/100) x (1 - d2/100). Sales tax, when entered, is applied to that final sale price by default, matching how most US retailers compute tax at checkout.

Worked example

Take a $100 item marked 20% off. The discount amount is $100 x 0.20 = $20, so the sale price is $80. Add a stacked 10% coupon on top: $80 x 0.10 = $8 more off, leaving a final sale price of $72 — a combined effective discount of 28% off the original $100, not 30%. With a 7% sales tax on that $72, the final price at checkout is $77.04.

What moves the savings most

  • The discount rate: savings scale directly with the percentage — doubling the discount rate roughly doubles the dollar amount saved on the same item.
  • Stacking order and math: two discounts of d1% and d2% never simply add. The combined discount is 1 - (1-d1/100) x (1-d2/100), which is always a little less than d1 + d2.
  • Sales tax timing: because tax is charged on the discounted price in most US states, a bigger discount also lowers the tax you pay, not just the sticker price.

Percentage off versus dollar off

To compare a "20% off" deal with a "$15 off" deal on the same item, convert the dollar discount into a percentage by dividing by the original price ($15 / $75 = 20%), or convert the percentage into a dollar amount by multiplying by the price. Whichever discount produces the lower final price is the better deal on that specific item — the comparison can flip entirely on a different priced item.

Frequently Asked Questions

How is a percentage discount calculated?
Multiply the original price by the discount rate to get the amount saved, then subtract that from the original price: Discount Amount = Price x (Discount% / 100), and Sale Price = Price - Discount Amount. A $100 item at 20% off saves $20, for a sale price of $80.
Do two stacked discounts add together?
No. Stacked discounts apply one after another to a shrinking price, so they multiply rather than add. A 20% discount followed by an additional 10% discount leaves 80% x 90% = 72% of the original price, a combined 28% off - not 30%.
Is sales tax calculated before or after the discount?
Most US retailers calculate sales tax on the discounted price, since tax applies to the amount actually paid. This calculator follows that convention by default. Manufacturer coupons and some jurisdictions tax the pre-discount price instead, so check the receipt or local rule if the exact tax figure matters.
How do I compare a percentage-off deal to a dollar-off deal?
Convert the dollar discount to a percentage by dividing it by the original price: a $15 discount on a $60 item is 15/60 = 25% off. Enter that percentage into the calculator to compare it directly against a competing percentage-off offer on the same item.

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