Percent Off Calculator

Find the discounted price, the dollar amount you save, and the final total after an optional second discount and sales tax.

Quick Facts

Formula
Final Price = Price × (1 − Discount ÷ 100)
Amount saved equals the original price minus the final price.
Stacked discounts multiply
20% + 10% off ≠ 30% off
A second discount applies to the already-discounted price, so two 20%/10% discounts together equal 28% off, not 30%.

Your Results

Calculated
Final price you pay
-
After discount(s) and sales tax
You save
-
Total dollar savings vs. original price
Price after discount
-
Before sales tax is applied
Effective discount
-
Combined percent off the original price

Ready

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

How the Percent Off Calculator works

This tool answers the everyday shopping question: if an item costs a certain amount and carries a percentage discount, what do you actually pay? It uses the standard percent-off formula, then optionally layers a second stacked discount and a sales tax rate so the final number matches what shows up at checkout.

The formula

For an original price P and a discount rate d (as a percentage), the discounted price is:

Final Price = P × (1 − d ÷ 100)

The amount you save is simply the original price minus the final price: Savings = P − Final Price, which is algebraically the same as P × (d ÷ 100). If a second stacked discount applies, it is calculated on the already-discounted price, not the original price — the calculator applies each discount in sequence.

Worked example

Take a $100 item marked 20% off. The discount is $100 × 0.20 = $20, so the final price is $80. Now add a second, stacked discount of 10% (a common "extra 10% off clearance" scenario): 10% of $80 is $8, bringing the price to $72. The two discounts together saved $28 on a $100 item — an effective discount of 28%, not the 30% you might get by simply adding 20% and 10%.

Why stacked discounts don't add up

Percentages taken in sequence multiply rather than add. Mathematically, two discounts of d₁ and d₂ leave you paying (1 − d₁/100) × (1 − d₂/100) of the original price. For 20% and 10%, that's 0.80 × 0.90 = 0.72, or 72% of the original price — 28% off. The gap between "add the percentages" and "multiply the remaining fractions" grows as the discounts get larger, so it matters most on big clearance and coupon-stacking deals.

Where sales tax fits in

In most U.S. states, sales tax is charged on the price you actually pay at the register — after any discounts, not before. This calculator follows that convention: it applies the sales tax rate you enter to the price after both discounts, so the final figure reflects what a typical receipt would show. Enter 0% if your item is tax-exempt or if you want to compare pre-tax prices only.

Reading the results

  • Final price you pay: the bottom-line number after all discounts and tax.
  • You save: the dollar difference between the original price and the price after discounts (before tax).
  • Price after discount: useful for comparing against a listed "sale price" before tax is added.
  • Effective discount: the combined percentage off the original price — handy for comparing a stacked-discount deal against a single flat discount.

Frequently Asked Questions

How do you calculate percent off?
Multiply the original price by the discount percentage divided by 100 to get the amount saved, then subtract that from the original price: Final Price = Original Price × (1 − Discount% / 100). For example, a $100 item at 20% off saves $20, for a final price of $80.
How do you calculate two discounts stacked together?
Stacked discounts multiply, they do not add. Apply the first discount to the original price, then apply the second discount to the already-discounted price. A 20% discount followed by a 10% discount leaves you paying 0.80 × 0.90 = 72% of the original price, an effective 28% off — not 30% off.
Does sales tax apply before or after the discount?
In almost all U.S. jurisdictions, sales tax is calculated on the discounted price, not the original price. This calculator applies any sales tax rate you enter after both discounts have been subtracted.
What does the effective discount percentage mean?
The effective discount is total dollars saved divided by the original price, expressed as a percentage. It reflects the combined impact of a primary discount plus any additional stacked discount, and is always slightly less than the sum of the individual percentages.

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