How the real BOGO discount works
A buy/get offer discounts only some items, so the advertised percentage is not the percentage saved on the whole purchase. The calculator totals the regular prices, applies the offer to the qualifying “get” item or items, and divides the dollar savings by the normal total.
For equally priced items, the shortcut is get quantity × get discount ÷ total quantity. Differently priced items require the actual prices and the retailer’s rule for choosing discounted items.
Promotion rules vary
Retailers may discount the lowest-priced qualifying item, a specifically identified item, or use other restrictions. Check the actual offer terms, eligible products, quantity limits, and whether items must be purchased in one transaction. This calculator does not assume every retailer applies promotions the same way.