Discount Calculator

Yes. In this discount calculator, the percent off is applied to the original price first to get the sale price, and then sales tax is calculated on that discounted amount. This matches the most common checkout logic: you save money before tax is added. If you enter a tax rate, the tool shows the sale price (pre-tax), the tax amount, and the final price so you can see exactly what changed. If tax is blank, it is treated as 0% and the results will clearly state that tax was not applied.

“Percent off” means a percentage reduction from the original price. If an item is 30% off, you save 30% of the original price, and you pay the remaining 70% as the sale price before tax. This calculator uses the formula Savings = P × (d/100) and Sale Price = P − Savings, where P is the original price and d is the discount percentage. It also supports optional tax and quantity so the final price matches what you would expect for multiple items at checkout.

Stacked discounts are not additive because each discount applies to the current reduced price, not the original price. For example, 20% off followed by 10% off does not equal 30% off. If the original price is 100, a 20% discount makes it 80. Then 10% off applies to 80, reducing it to 72. The total savings are 28, so the effective discount is 28%. This discount calculator shows each step and the effective discount rate, which is the cleanest way to compare stacked offers.

In real shopping, a discount over 100% usually doesn’t make sense because it would imply paying a negative price. However, you might enter values above 100% when testing scenarios, modeling rebates, or checking edge cases. This calculator allows discount percentages above 100% but shows a warning because the results can become unusual. For “Find Original Price,” a 100% discount is blocked because it would require dividing by zero. If you see an unexpected value, reduce the discount or verify whether your inputs represent a rebate or a separate credit.

Prices like 19.99 can create repeating decimals after percent calculations, which is normal. This discount calculator keeps internal precision high, then rounds only for display based on your selected precision (0, 2, or 4 decimals). If you are matching a receipt, choose 4 decimals to see intermediate amounts more clearly. If you are budgeting, 2 decimals usually matches typical currency rounding. Because different stores may round at different steps, small differences of a cent can occur; the tool’s step-by-step breakdown helps you see where rounding affects the final price.

If the sale price is higher than the original price, the “discount” becomes negative, which effectively means a price increase (a surcharge). This can happen if you entered the values in the wrong fields, if shipping or fees were included in the sale price, or in return/exchange scenarios where the “sale” total includes extra items. The calculator will still compute the percentage change and label it clearly as a price increase so the math remains consistent. Double-check that both prices are pre-tax if you are comparing percent off offers.

Use the effective discount rate whenever you have multiple discounts or coupons applied sequentially. The effective rate compresses the entire chain of stacked discounts into one comparable percentage based on the original price. This makes it easier to compare two deals: for example, “20% then 10%” versus “25% off.” The discount calculator computes effective discount as (Total Savings / Original Price) × 100 and shows both the final sale price and the effective percent saved. It is especially useful when quantities and tax are included because you can compare totals using one consistent rate.

Percent discounts reduce the price by a percentage of the current amount, while coupons can be either a percent off or a fixed amount off. This calculator focuses on percent off and stacked percent discounts because they are the most common and require careful sequential math. If you have a fixed-amount coupon, you can convert it into an equivalent percent off for a quick comparison by dividing the coupon value by the original price and multiplying by 100. Then you can use the percent off mode to estimate the sale price and final price, especially when sales tax and quantity matter.