Discount Calculator - Sale Price and Savings

A discount calculator converts an original price into a sale price, a dollar saving, and an effective discount percentage. Shoppers use it to compare promotions. Merchants use it to check that a stated percent-off or dollar-off offer produces the intended ticket price. The form accepts either a percentage or a fixed amount; if both are present, the percentage takes precedence so the primary percent-off workflow stays unambiguous. When a percentage is entered, discount amount = original price × percentage ÷ 100 and sale price = original price − discount amount. When only a dollar amount is entered, that amount is subtracted and the effective percentage is amount ÷ original price. A $100 item at 25% off saves $25 and sells for $75.00. A $250 item with a $40 markdown sells for $210.00, which is a 16.00% effective discount. The calculator rejects a discount larger than the original price so the sale price cannot go negative. Use it to compare a percent-off coupon with a fixed-amount coupon, to verify a POS markdown, or to back into the percentage implied by a “now $X” price. Stacked discounts, member prices, and quantity breaks need to be applied in the order the offer specifies; this form models a single markdown. Currency is USD formatting only—the arithmetic is the same in any currency as long as original price and amount use the same unit. Sales tax, shipping, and cash-back rebates are not applied. Tax is usually computed on the discounted price, but local rules differ for coupons versus retailer markdowns. Rounding at the register can differ by a cent from two-decimal banker's rounding. Treat the result as the pre-tax advertised price, then apply tax and fees according to the receipt rules that actually govern the purchase. For stacked promotions, apply the first discount, then use the new sale price as the original price of a second run. That sequence matches most “extra 10% off already-reduced items” language better than adding percentages. If a coupon is a fixed amount, clear the percentage field so the amount path is used. The effective discount percentage is always discount amount divided by the original price you entered, which makes percent-off and dollars-off offers comparable on one ticket.