What's the difference between a percentage discount and a fixed-amount discount?

A percentage discount scales with the price: 20% off $100 saves $20, but 20% off $10 only saves $2. A fixed discount (like a $10 coupon) saves the same dollar amount regardless of price, so which one saves more depends on the price.

Can I stack discounts?

Yes. A double discount, or two successive discounts, applies the second to the already-reduced price, so the order matters: "20% off plus 10% off" is not 30% off: $100 → -20% = $80 → -10% = $72. That is an effective 28% discount, not 30%.

How do I calculate what percentage off an item is?

Percent off, the discount percentage, = ((Original Price - Sale Price) / Original Price) × 100. For example, an item that was $80 and is now $60: ($20 / $80) × 100 = 25% off. Switch to "Find % Off" mode and enter both prices to get this instantly, without doing the math yourself.

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

Divide the sale price by 1 minus the discount as a decimal. A price of $42 after 30% off was $42 ÷ 0.70 = $60. With an amount off, add it back: $60 after a $15 coupon was $75. Switch to Find Original mode and enter the sale price and the discount. Use the price before sales tax: a receipt total that includes tax gives an original price that is too high.

What is the effective discount rate when multiple coupons are stacked?

For two percentage discounts, the effective rate is 1 - (1 - D1) × (1 - D2): 20% and 10% gives 1 - 0.80 × 0.90 = 28%. With an amount off, the second step works on the reduced price, and the effective rate is the total saved ÷ the original price. Turn on "Add Stacked Discount" to enter the two.

Does the discount apply before or after sales tax?

A store's own discount or coupon generally comes off the price that sales tax is charged on. A manufacturer's coupon, one marked as the manufacturer's own, may be taxed on the price before the coupon, and New York does this. In California the manufacturer's payment counts in the store's taxable sales, and the store may charge tax on it by contract. Rules differ by state, so check your state's tax agency.

Discount Calculator - Sale Price & Percent Off

Discount Details

Calculate final sale price with percent or fixed discounts, including stacked discount scenarios. See total savings and effective discount rate.

Choose a mode

Enter the original price

Enter the discount or sale price

Add a stacked discount (optional)

This applies your discounts in the order you entered them and never below zero. A checkout can stack, cap or order discounts differently, so the receipt total may differ.

Formulas and sources

Each formula this calculator uses, where it comes from, and what it leaves out. "How it works" shows the same formula with your own numbers.

Final price, percentage off

Simple mode, with one percentage discount

Final Price = P × (1 − D)

Final Price: the price after the discount
P: the original price
D: the discount as a share of P (20% is 0.20)

A percentage above 100 is not accepted, and the price never goes below zero.