About this tool
A BOGO vs discount calculator (1+1 할인 비교, bonus-item deal vs sale price) answers a common shopping question: is 1+1 really cheaper than 30% off?
Enter the price of one item, the deal (buy A, get B free) and the percent-off price you are comparing, then the number of items you actually need.
The effective unit price of a bonus deal is price x A / (A + B), so 1+1 equals 50% off, 2+1 equals about 33.3% off and 3+1 equals 25% off.
The bonus deal only wins when its equivalent rate is higher than the discount rate, and only if you will really use all the extra items. Example: an item costs 3,000 won, you need 2, and the choices are 1+1 or 30% off.
1+1 costs 3,000 won in total and 30% off costs 2 x 3,000 x 0.7 = 4,200 won, so 1+1 saves 1,200 won.
Now a 2+1 deal against 40% off for 3 items: 2+1 costs 6,000 won and 40% off costs 5,400 won, so the discount wins by 600 won. What if you need only 1 item?
The 1+1 deal still charges 3,000 won (you receive 2), while 30% off costs 2,100 won, so the discount is cheaper unless you can use or share the extra one. Does the tool include shipping or points?
No, add them to the price yourself. For a plain percent-off price use the discount calculator, to compare sizes use the unit price calculator, and for several coupons use the coupon stack calculator.
Results are for reference only.
How to use
- Enter the price of one item and the deal: buy A, get B free.
- Enter the percent-off rate you are comparing and how many items you need.
- Read which option costs less in total and how much you save.