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Discount Calculator

Find the sale price from a price and percent off, the discount rate from an old vs. new price, the original price behind a sale price, and the true total of stacked (sequential) discounts — all in one tool, with instant, plain-English results.

Stacked discounts calculated right Sales tax included/excluded Cart total discount Updated: Jul 22, 2026
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Subtracts a fixed dollar amount instead of a percentage (a coupon, gift card, or store credit).
Know the old and new price? Find the discount rate that was applied:
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Know the sale (paid) price and the discount rate that was applied? Find the original price:
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Add the discounts in the order they're applied (each one is calculated on the price left over from the last, never added together):
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Compare two competing discounts — a single % or $ off, or a stacked combo — and see which one actually costs less.
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Add a second stacked % (optional, e.g. an extra coupon on top).
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Add a second stacked % (optional, e.g. an extra coupon on top).
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⚙️ Advanced settings — sales tax
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Rates vary by state and locality — enter your own.
Entered price includes sales taxTurn off if the price is pre-tax
Quick answer A discounted price is found by multiplying the original price by the coefficient (1 − discount rate ÷ 100): Discounted price = Price × (1 − Discount ÷ 100). Stacked discounts are never simply added together — each new discount is calculated on the price left over from the previous one. For example, a 20% discount followed by a 10% discount doesn't total 30%; it's equivalent to 28%.
$1,000 → $800with a 20% discount
28%20% + 10% stacked equivalent
Half price50% discount
33.3%"buy 3, pay for 2" equivalent
🧮 Note: All results use standard discount math: Discounted price = Price × (1 − Discount ÷ 100). In stacked discounts, each step is applied to the price left over from the last one — the rates are never simply added together. Sales tax figures use the rate you enter (rates vary by state and locality). Results are for informational purposes only — confirm exact promotion terms with the seller.
🏷️ Discount Calculator — ToolPico ↗

What is a discount calculation, and how is it done?

A complete guide — with formulas and examples — to discounted prices, discount rates, stacked (sequential) discounts, and cart totals.

A discount calculation finds the sale price a shopper pays after a discount rate or a fixed dollar amount is subtracted from a product's original price. A single discount is straightforward; most of the confusion shows up with the stacked (sequential) discounts common in promotions, and with whether a price tag is tax-included or tax-excluded. This calculator computes in three directions — price-to-sale-price, old-to-new-price, and sale-to-original-price (reverse) — plus stacked discounts, and shows exactly why sequential discounts are never simply added together.

How do you calculate a discounted price?

Quick answerDiscounted price = Price × (1 − Discount rate ÷ 100). For example, a $500 item with a 15% discount costs 500 × 0.85 = $425, a savings of $75. With a fixed dollar discount, it's even simpler: Discounted price = Price − Discount amount.

How are stacked (sequential) discounts calculated? Do they add up?

Quick answerIn a stacked discount, each rate is applied separately to the price left over from the previous discount — the rates are never simply added together. Formula: Final price = Price × (1−rate1/100) × (1−rate2/100) × ... For example, a 20% discount followed by a 10% discount equals 1 − 0.80×0.90 = 28% total, not 30%.

This is the most commonly misunderstood part of discount math. Most simple calculators only support a single discount rate; the Stacked Discount tab above lets you chain as many sequential discounts as you like and shows both the final price and the "equivalent single discount" rate at the same time.

How do you find the discount rate from an old and a new price?

Quick answerRate (%) = ((Old price − New price) ÷ Old price) × 100. For example, an $800 item that drops to $600 has a discount rate of (800−600)÷800×100 = 25%. Just enter both prices in the "Old → New" tab.

What should you watch for with a discount on a tax-included price?

Quick answerA price tag is usually tax-inclusive; the discount is applied directly to that amount, and the discounted price comes out tax-inclusive too. To see the pre-tax equivalent, divide the discounted price by (1 + tax rate ÷ 100). Use "Advanced settings" above to enter your local sales tax rate and whether the entered price already includes it.

How do you calculate the total discount for a cart with multiple items?

Quick answerEach item's discounted price is calculated separately, then added together for the cart total. The cart's average (effective) discount rate is the total savings divided by the total normal price, and can differ from a simple average if items have different rates. Add your own items in the "Cart" section below.

What's the real discount rate on "buy X, pay for Y" promotions?

Quick answerReal rate = (1 − Quantity paid ÷ Quantity bought) × 100. "Buy 3, pay for 2" equals (1−2/3)×100 ≈ 33.3% off, and "buy 2, pay for 1" equals 50% off. Use the mini tool below with your own unit price and quantities to see the total savings.

Common discount amounts (example table)

Common discount rates and savings for a round-number item. Use the calculator above for your own exact price.

Discount rates and savings for a $1,000 item
Discount rateSale priceYou save
10%$900$100
15%$850$150
20%$800$200
25%$750$250
30%$700$300
40%$600$400
50%$500$500
60%$400$600
70%$300$700

Popular calculations

Cart total discount calculator

Add multiple items with a price and discount rate; instantly see the cart's total, total savings, and average (effective) discount rate.

Related mini calculators

Find the real rate behind "buy X, pay for Y" bulk deals, a coupon stacked on top of a sale, and "second item X% off" (BOGO-style) promotions.

🛍️Buy X, Pay for Y
Find the real discount rate on bulk deals like "buy 3, pay for 2" or "buy 2, pay for 1".
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🎟️Coupon on a Sale Price
Find the real amount you'll pay when a coupon code is applied on top of a sale.
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🥈Second Item X% Off (BOGO)
"Second item 50% off" and similar BOGO-style promos — find the total payable and effective rate.
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Reference tables & practical examples

Citable example tables: common discount rates, stacked-discount equivalents, and "buy X, pay for Y" equivalents.

Common discount rates for a $1,000 item
Discount rateSale priceSavings
10%$900$100
15%$850$150
20%$800$200
25%$750$250
30%$700$300
40%$600$400
50%$500$500
60%$400$600
70%$300$700

Formula: Discounted price = Price × (1 − Rate ÷ 100). Use the calculator above for a different price.

Stacked (sequential) discount equivalence table
Stacked discountNaive sum (wrong)Real equivalent rate
10% + 10%20%19%
20% + 10%30%28%
20% + 20%40%36%
30% + 10%40%37%
20% + 30%50%44%
30% + 10% + 5%45%40.2%
50% + 20%70%60%
40% + 30% + 10%80%62.2%
50% + 30%80%65%

Order doesn't change the result: 20%+30% and 30%+20% both give the same 44% equivalent. Formula: 1 − Π(1 − rateᵢ/100).

Real discount rate for "buy X, pay for Y" deals
DealReal discount rate
Buy 6, pay for 516.7%
Buy 5, pay for 420%
Buy 4, pay for 325%
Buy 3, pay for 233.3%
Buy 2, pay for 1 (one free)50%
Buy 3, pay for 166.7%

Formula: (1 − Quantity paid ÷ Quantity bought) × 100. Use the "Buy X, Pay for Y" mini tool above with your own unit price to see the total savings.

Discount terms glossary

Short definitions of the core terms used in discount and promotion math.

Original priceThe price on the tag or listing before any discount is applied.
Discount rateThe percentage subtracted from the original price. Discounted price = Price × (1−Rate÷100).
Stacked (sequential) discountMultiple discounts applied one after another, each on the price left over from the last. Rates are never added together.
Equivalent single discount rateThe single discount rate that stacked discounts add up to overall.
Cart discountThe total savings across all items in a cart, from the difference between the total normal price and the total discounted price.
Tax-included / tax-excluded priceWhether a price already includes sales tax. US price tags are usually tax-excluded; tax is added at checkout.
Buy X, Pay for YA promotion where a customer buying a certain quantity pays for fewer units (e.g. buy 3, pay for 2).
Net savingsThe difference between the original price and the discounted price — the amount that stays in your pocket.

In-depth guides

Worked examples for the most commonly confused discount questions.

How much do a 20% and 10% stacked discount really add up to? (worked example)

A $1,000 item first gets a 20% discount, dropping the price to 1,000 × 0.80 = $800. Then a 10% discount is applied to that $800 (not to the original $1,000!): 800 × 0.90 = $720. Total savings is 1,000 − 720 = $280, so the equivalent single discount rate is 28% — not 30%.

Enter the price and both rates in the "Stacked Discount" tab above and hit Calculate to see each step and the total equivalent rate.

What's a $1,000 item after a 30% discount?

A $1,000 item with a 30% discount has a sale price of 1,000 × (1 − 0.30) = 1,000 × 0.70 = $700. The savings amount is $300. You can confirm this in the "Price + %" tab by entering a $1,000 price and a 30% rate.

If the discount amount is a known fixed dollar figure (say, a $300 coupon) instead, switch to "$ Discount (fixed amount)" in the same tab and enter the amount directly — the result is the same.

How does a coupon code stack on top of a sale price?

If a store item is already 20% off in a sale, and a shopper applies an extra 10% coupon code at checkout, the coupon is calculated on the already-discounted sale price — not on the original price. That's the exact same stacking logic as above: the two discounts combine multiplicatively into a total equivalent of 28%, not 30%.

Use the "Coupon on a Sale Price" mini tool above with your own price and rates to see this difference in seconds.

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Frequently asked questions

How do you calculate a discount percentage?
A discount percentage is the discount amount divided by the original price, multiplied by 100: Discount rate (%) = (Discount amount ÷ Original price) × 100. If you're starting from a sale price, first find the difference (old price − new price), then divide that difference by the old price and multiply by 100. For example, a $1,000 item with a $200 discount has a 20% discount rate.
How do you calculate stacked (sequential) discounts?
In a stacked (sequential) discount, each discount is applied separately to the price left over from the previous discount — the rates are never simply added together. Formula: Final price = Price × (1 − rate1/100) × (1 − rate2/100) × ... For example, a 20% discount followed by an extra 10% off doesn't total 30% — it equals 1 − 0.80×0.90 = 28%.
What do a 20% and a 30% discount add up to when stacked?
A 20% discount followed by a 30% discount, applied sequentially, doesn't total 50% — it equals 1 − (1−0.20)×(1−0.30) = 1 − 0.80×0.70 = 44%. Order doesn't change the result: applying 20% then 30% gives the same 44% equivalent as applying 30% then 20%.
How do you calculate a discounted (sale) price?
A discounted price is found by multiplying the original price by (1 − discount rate ÷ 100): Discounted price = Price × (1 − Rate ÷ 100). For example, a $500 item with a 15% discount costs 500 × 0.85 = $425, a savings of $75.
How do you find the discount rate from an old and a new price?
If you know the old (original) price and the new (sale) price, the discount rate is: Rate (%) = ((Old price − New price) ÷ Old price) × 100. For example, an $800 item that drops to $600 has a discount rate of (800−600)÷800×100 = 25%.
How do you calculate the total discount on a cart with multiple items?
When a cart has multiple items, calculate each item's discounted price separately, then add all the discounted prices together for the cart total. The cart's average (effective) discount rate is the total savings divided by the total normal price — if the items have different discount rates, this can differ from a simple average of the individual rates.
How does sales tax affect a discount calculation?
A price tag is usually tax-inclusive, so the discount is applied directly to that tax-inclusive amount, and the discounted price comes out tax-inclusive too. To see the pre-tax amount, divide the discounted price by (1 + tax rate ÷ 100); for example, a $240 price with 20% tax included has a pre-tax equivalent of 240 ÷ 1.20 = $200.
What's the real discount rate on a "buy X, pay for Y" deal?
The real discount rate on a "buy X, pay for Y" deal (e.g. buy 3, pay for 2) is found with (1 − Quantity paid ÷ Quantity bought) × 100. For example, "buy 3, pay for 2" equals (1 − 2/3) × 100 ≈ 33.3% off, and "buy 2, pay for 1" equals 50% off.
How do you find the original price from a sale price?
If you know the sale price and the discount rate that was applied, the original price is: Original price = Sale price ÷ (1 − Discount rate ÷ 100). For example, an item on sale for $750 at 25% off had an original price of 750 ÷ 0.75 = $1,000. Just enter both values in the "Sale → Original" tab above.
How much total discount does a "second item 50% off" (BOGO) promotion give?
If both items are the same price, a "second item X% off" promotion's total (effective) discount is half of X — because the discount only applies to one item, and spreading it across both items' combined total cuts the rate in half. For two equally priced items, "second item 50% off" equals 25% off the whole purchase, and "second item 30% off" equals 15% off. If the prices differ, the discount is usually applied to the cheaper item and the effective rate changes; see the "Second Item X% Off" mini tool above.
Is "3-for-2" the same as "buy 3, pay for 2"?
Yes — "3-for-2" and "buy 3, pay for 2" describe the exact same promotion: take three units, pay for only two. The real discount rate is (1 − Quantity paid ÷ Quantity bought) × 100 = (1 − 2/3) × 100 ≈ 33.3% off the normal total. The same logic applies to "2-for-1" (buy 2, pay for 1 = 50% off) and "4-for-3" (buy 4, pay for 3 = 25% off). Use the preset chips on the "Buy X, Pay for Y" mini tool above to try each one instantly.

Methodology & sources

ToolPico's Discount Calculator is a free, independent tool. The calculation engine uses standard discount arithmetic: a single discount is Price × (1 − Rate ÷ 100); stacked (sequential) discounts apply each rate multiplicatively to the price left over from the previous step — the rates are never added together; the discount rate between two prices is (Old − New) ÷ Old × 100; the original price from a sale price is Sale price ÷ (1 − Rate ÷ 100); and cart totals sum each item's discounted price individually. Sales tax figures use the rate you enter, since tax rates vary by US state and locality.

Basis: Standard mathematics (ratio and proportion). Last updated: July 22, 2026. Results are computed instantly client-side (in your browser); no data is sent to a server. Results are for informational purposes only — confirm exact promotion terms, taxes, and totals with the seller or your local tax authority.

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