Discount Calculator

Calculate discounts, sale prices, and savings.

What Is a Discount Calculator?

A discount calculator determines the sale price, savings amount, or discount percentage when buying items on sale. It takes the guesswork out of shopping math by instantly computing what you will actually pay after one or more discounts are applied, optionally including sales tax. Whether you are comparing deals across stores, calculating clearance prices, or figuring out how much you saved, this tool provides immediate answers.

Discounts are everywhere in retail: seasonal sales, clearance events, coupon codes, loyalty rewards, employee discounts, and volume pricing. Understanding the actual dollar impact of different percentage discounts helps you make informed purchasing decisions and avoid marketing tactics that make deals appear better than they are.

How Discount Calculations Work

The core calculation for finding a sale price from a discount percentage is straightforward:

Discount Amount = Original Price x (Discount Percentage / 100)

Sale Price = Original Price - Discount Amount

To find the discount percentage when you know both prices:

Discount Percentage = ((Original Price - Sale Price) / Original Price) x 100

To find the original price from the sale price and discount:

Original Price = Sale Price / (1 - Discount Percentage / 100)

Stacked discounts apply sequentially. When a second discount is applied on top of the first, it reduces the already-reduced price, not the original:

Final Price = Original x (1 - First Discount/100) x (1 - Second Discount/100)

This is why a 20% discount plus a 10% discount equals a 28% total discount, not 30%. The second discount applies to 80% of the original price, so 10% of 80% is 8%, giving a combined 28%.

Sales tax is calculated on the final discounted price:

Tax Amount = Discounted Price x (Tax Rate / 100)

Final Total = Discounted Price + Tax Amount

How to Use This Calculator

Select the calculation type. Choose from three modes: calculate the sale price from a discount percentage, calculate the discount percentage from two known prices, or calculate the original price from the sale price and discount percentage.
Enter the required values. Depending on the mode, enter the original price and discount percentage, or the original and sale prices, or the sale price and discount percentage. The calculator shows and hides the appropriate fields based on your selection.
Use quick discount buttons (optional). Click the preset buttons (10%, 15%, 20%, 25%, 30%, 50%, 75%) to quickly set common discount levels. These are helpful for comparing different discount offers.
Add a stacked discount (optional). If you have an additional coupon or promotion that applies on top of the first discount, enter it in the "Additional Discount" field. The calculator applies it to the already-reduced price.
Enter sales tax (optional). If you want to see the final out-of-pocket cost including tax, enter your local sales tax rate. Tax is calculated on the price after all discounts.
Review the results. The summary shows the original price, each discount amount and percentage, the final price you pay, and the total savings. A detailed breakdown shows every step of the calculation.

Worked Examples

Example 1: Simple Percentage Discount

A jacket costs $89.99 and is marked 30% off. Discount amount: $89.99 x 0.30 = $27.00. Sale price: $89.99 - $27.00 = $62.99. You save $27.00.

Example 2: Finding the Discount Percentage

A TV was $599.99 and is now $449.99. Discount: $599.99 - $449.99 = $150.00. Percentage: ($150.00 / $599.99) x 100 = 25.0%. The store is offering a 25% discount.

Example 3: Stacked Discounts

A store has a 25% off sale, and you have an additional 15% off coupon. On a $200 item: first discount: $200 x 0.25 = $50, reduced to $150. Second discount: $150 x 0.15 = $22.50, reduced to $127.50. Total saved: $72.50 (36.25% total discount, not the 40% you might assume by adding 25% + 15%).

Example 4: Discount with Sales Tax

A laptop costs $999.99 with a 20% student discount and 8.25% sales tax. Discount: $999.99 x 0.20 = $200.00. After discount: $799.99. Tax: $799.99 x 0.0825 = $66.00. Final total: $865.99. Without the discount, the total would have been $1,082.49, so you save $216.50 in total.

Tips for Smart Shopping

Compare the dollar savings, not just the percentage. A 40% discount on a $20 item saves $8, while a 15% discount on a $200 item saves $30. The smaller percentage can represent much larger savings in absolute terms. Always calculate the actual dollar amount before deciding which deal is better.

Watch out for inflated "original" prices. Some retailers raise the displayed original price before a sale to make the discount appear larger. Compare the sale price to prices at other stores rather than relying solely on the stated discount percentage. Price tracking tools and browser extensions can show historical pricing data.

Understand the order of stacked discounts. Mathematically, the order in which sequential percentage discounts are applied does not affect the final price (20% then 10% gives the same result as 10% then 20%). However, some stores may calculate them differently or cap total discounts, so check the specific terms.

Factor in sales tax for accurate budgeting. The sticker price after discount is not what comes out of your wallet. Adding the sales tax field gives you the true final cost. Tax rates vary by state and locality, typically ranging from 0% to over 10% in the United States.

Compare BOGO to percentage discounts carefully. Buy-one-get-one-free is 50% off only if you need both items. If you only need one, a straight 25% off is a better deal because you spend less money overall. BOGO is designed to increase total purchase amount, which benefits the retailer.

Check for price-match guarantees. Many retailers will match a competitor's lower price. Calculate the effective discount compared to the original price at each store, and present the better deal for a price match rather than settling for whatever sale is advertised at the store where you are shopping.

Frequently Asked Questions

How do I calculate the sale price after a discount?

Multiply the original price by the discount percentage divided by 100, then subtract that amount from the original price. For example, a $80 item at 25% off: $80 x (25/100) = $20 discount. Sale price: $80 - $20 = $60. Alternatively, multiply the original price by (1 - discount/100): $80 x 0.75 = $60. Both methods produce the same result.

How do I find the discount percentage from two prices?

Subtract the sale price from the original price to get the discount amount, then divide the discount amount by the original price and multiply by 100. For example, if an item was $120 and is now $90: ($120 - $90) / $120 x 100 = 25%. The calculator automates this by selecting the 'Calculate discount % from prices' mode.

How do I find the original price from the sale price and discount percentage?

Divide the sale price by (1 - discount/100). For example, if you paid $60 after a 25% discount: $60 / (1 - 0.25) = $60 / 0.75 = $80. This calculation works because the sale price represents the percentage of the original price that you actually paid (75% in this case).

How do stacked discounts work?

Stacked discounts apply sequentially, not by adding the percentages together. A 20% discount followed by an additional 10% discount does not equal 30% off. Instead, the first discount reduces the price to 80% of the original, and the second discount reduces that result to 90% of the reduced price. The combined effect is 0.80 x 0.90 = 0.72, or 28% total discount, not 30%.

Should I calculate the discount before or after sales tax?

Discounts are applied before sales tax in virtually all retail situations. The sales tax is calculated on the final discounted price, not the original price. For example, a $100 item at 20% off with 8% tax: discounted price is $80, tax is $80 x 0.08 = $6.40, and the final total is $86.40. This calculator follows this standard order of operations.

How do I compare a percentage discount to a fixed dollar discount?

To compare, convert the dollar discount to a percentage or vice versa. If a store offers $15 off or 20% off a $60 item: the $15 off gives a sale price of $45 (25% discount), while 20% off gives a sale price of $48 ($12 savings). The dollar discount is better in this case. Generally, percentage discounts become more valuable as the price increases, while fixed dollar discounts are more valuable on lower-priced items.

What is a BOGO deal and how does it compare to a percentage discount?

BOGO means Buy One Get One free, which is effectively a 50% discount when you buy exactly two items. However, BOGO requires purchasing two items, so the savings depend on whether you actually need both. A straight 50% off one item costs less total money ($50 for one item vs. $100 for two with BOGO on a $100 item). BOGO is better value per unit but costs more overall because you must buy two.

How do I calculate savings on bulk or tiered pricing?

Tiered pricing offers different discounts based on quantity. Calculate each tier separately. For example, buy 1-5 at full price, 6-10 at 10% off, 11+ at 20% off. For 15 items at $10 each: 5 x $10 = $50, plus 5 x $9 = $45, plus 5 x $8 = $40. Total: $135 instead of $150, for an average discount of 10%. Use this calculator for each tier and sum the results.