Discount Calculator

How is a discount calculated?

Enter the list price and discount rate to find the sale price. With list price L, sale price S and percentage rate p, the formula is S = L × (1 − p/100). The discount amount is the difference between L and S. If both prices are known, the rate is 100 × (L − S)/L.

Successive discounts

Discount rates are not added together. Each discount applies to the price left after the previous one. For example, a price of 1000 reduced by 20 percent and then 10 percent becomes 1000 × 0.8 × 0.9 = 720. The equivalent discount is 28 percent. Set the third rate to zero when applying only two discounts.

Original price and limits

Divide the sale price by the remaining fraction. A sale price of 600 after a 25 percent discount gives 600/0.75 = 800. A 100 percent discount cannot be reversed. The list price must be positive when finding a rate. Enter all amounts on the same monetary scale. Tax and payment terms are excluded. Intermediate calculations are not rounded, while displayed amounts have two decimal places.

Comparing the same price basis

Check that both prices have the same tax status and refer to the same product quantity. Comparing a unit price with a package price cannot be resolved by a discount rate alone. The calculator does not align currencies or price scope automatically.

For example, reduce a list price of 200 by 25 percent and then 20 percent. The first price is 200 × 0.75 = 150, and the second is 150 × 0.8 = 120. Total discount is 80 and the equivalent rate is 40 percent. Adding the rates to obtain 45 percent is wrong because the second discount no longer applies to the original price.

For the same reason, adding the discount percentage to the sale price does not recover the list price. Divide by the remaining price fraction. Here that is 0.6, giving 120/0.6 = 200. In list price mode, enter the equivalent rate, here 40 percent. Displayed money is rounded while intermediate calculations retain full values. Different invoice line rounding rules can produce different totals. This preliminary price calculation does not assess the economic effect of payment terms.