About the BOGO Calculator
Buy-one-get-one offers sound generous, but the headline rarely matches the real discount. This BOGO calculator converts any “buy X, get Y at Z% off” promotion into the numbers that matter: what you pay at the register, how much you save, the effective percentage off every item and the price you are really paying per unit.
Use it in the supermarket, pharmacy or clothing store to compare a BOGO deal with a straight percentage discount, to check whether buying an extra item is worth it, or to see what happens when your basket does not divide evenly into the deal. Buy one get one free is only 50% off when you buy exactly two, and BOGO 50% off is really 25% off each item.
The calculator assumes every item has the same price. When prices differ, stores usually discount the cheaper item, so your actual saving can be lower.
With the default inputs, the effective discount is 50%. Change any value above to recalculate instantly.
How to use the bogo calculator
- 1Enter the regular price of one item.
- 2Enter the deal: how many you buy and how many you get.
- 3Set the discount on the “get” items — 100% for free, 50% for half off.
- 4Enter how many items you plan to buy.
- 5Compare the effective discount with other offers in the store.
Formula and method
A “buy X, get Y at Z% off” deal works in groups of X + Y items. Every complete group earns Y discounted items, and any leftover items beyond the first X in a partial group are discounted too. The total you pay is the regular price of all N items minus the discount on those discounted items.
The effective discount is your total saving divided by the regular price of everything in the basket. For a full group this simplifies to Y × Z ÷ (X + Y): BOGO free is 1 × 100% ÷ 2 = 50%, BOGO half off is 25%, and buy 2 get 1 free is 33.3%.
- X
- Items bought at full price per deal
- Y
- Items received at a discount per deal
- Z
- Discount on the Y items (100% = free)
- N
- Items in your basket
Worked examples
Buy one get one free on a $10 item
Two items normally cost $20. With one free you pay $10 and save $10, which is 50% off — an effective $5 per item.
BOGO 50% off, buying four at $8.99
Four items form two deal pairs, so two items are half price. You pay $35.96 − 2 × $4.495 = $26.97 and save $8.99. That is only 25% off overall, or about $6.74 per item.
Buy 2 get 1 free, six items at $4.50
Six items make two groups of three, so two are free. You pay for four ($18 instead of $27), saving $9 — an effective 33.3% off and $3 per item.
Frequently asked questions
Is buy one get one free the same as 50% off?+
Only when you buy an even number of identical items. Two items at BOGO free cost the same as two at 50% off, but if you only need one item, a 50% discount is better because BOGO gives you nothing off a single item.
How much is BOGO 50% off really?+
Buy one get one 50% off is an effective 25% discount on each item: you pay 1.5 prices for 2 items. It is a smaller saving than it sounds.
What percent off is buy 2 get 1 free?+
Buy two, get one free means you pay for 2 out of every 3 items, which is an effective discount of 33.3% on each item when you buy in multiples of three.
Which item is free in a BOGO deal with different prices?+
Most retailers apply the discount to the lower-priced item (or the item of equal or lesser value). Pair items of similar prices to get the most out of the deal.
Is BOGO a good deal?+
It is a good deal if you would buy and use both items anyway. If the extra item goes unused, your real saving is lower — compare the per-item price with a straight discount or the store brand.