Where the numbers come from: every figure on this page is a worked example computed by the calculator above, and the line behind each answer is shown with it. Worked examples are not market prices, and no deal or third-party price is quoted anywhere on this page.
What is buy one get one half price really worth?
Buy one, get one half price works out to 25 % off across the two items: on two $40 items you pay $60.00 at the register and keep $20.00. “Half price” describes the second item only; the pair is what lands in your basket, and the percent must be worked out on the pair, not on the tag.
It is a good deal exactly when you needed two of the thing anyway: each item then costs $30.00 instead of $40.00. If you only wanted one, the offer just talked you into a second one. The calculator above takes the quantity, so you can see what taking 3 or 4 does before the basket decides for you.
| Offer, on two $40 items | You pay | Effective discount |
|---|---|---|
| Buy one, get one half price | $40 + $20 = $60.00 | 25 % off |
| Buy one, get one free | $40.00 | 50 % off |
| 3 for 2 (three items) | 2 × $40 = $80.00 | 33.33 % off |
| 4 for 3 (four items) | 3 × $40 = $120.00 | 25 % off |
| Straight 30 % off, both items | 2 × $28 = $56.00 | 30 % off |
These are worked examples on a $40 item, not shelf prices; the habit is the product. The calculator above recomputes every row of this thinking for your own tag price, and the Black Friday preset runs the whole deal-season set: stacked tags, per-unit packs and the till line with tax and shipping.
What does the offer do when you take 3, or 4?
Only whole pairs earn the discount. On $40 items: two pay $60.00; three pay $100.00, because the third item sits outside every pair and pays full price; four pay $120.00. However many you take, the whole basket never gets past the pair’s 25 % off; it only approaches it.
| You take | You pay | You keep vs. full price | Effective discount |
|---|---|---|---|
| 2 items | $60.00 | $20.00 | 25 % off |
| 3 items | $100.00 | $20.00 | 16.67 % off |
| 4 items | $120.00 | $40.00 | 25 % off |
That 16.67 % is the honest number a headline never shows: the tag says half price, and a third item in the basket earns nothing. Sellers count on the extra item, and the calculator above counts the pairs.
Is that better than a straight percent off?
Convert both to their effective percent and compare one number. On two $40 items, buy one get one half price is 25 % off: a straight 25 % off leaves exactly the same $60.00, a straight 30 % off beats it at $56.00, and buy one, get one free (50 % off) beats them all. The offer wins on the spreadsheet only if you truly needed the second item.
Can “buy one get one” stack with another percent off?
When a seller allows it, the tags multiply; they never add. A 25 %-effective BOGO followed by an extra 20 % off the whole basket is not 45 % off: 0.75 × 0.80 = 0.60, which is 40 % off. Whether the second tag applies to a BOGO basket at all is store policy, not math, and the receipt is what settles it.
That multiply rule is the job a “double discount calculator” is asked to do: the stacked discounts tab above works any pair (plus an optional third tag) and names the true number, and the true checkout tab adds the tax and shipping the tags never mention.
Questions
Is buy one get one half price the same as 50 % off?
No. The half price applies to the second item only: two $40 items cost $60.00, which is 25 % off the $80.00 full price. Buy one, get one FREE is the one that works out to 50 % off two equal items.
How do I compare a BOGO offer with a straight percent off?
Turn the offer into its effective percent and compare one number. Half price off the second of two equal items is 25 % off, so a straight 30 % off wins. The calculator above shows the effective percent next to the register total.
What happens if I take three items?
Only whole pairs earn the discount, so the third item pays full price: three $40 items cost $100.00, which is 16.67 % off, not 25 %. Take two pairs (four items) and you are back at 25 %.
Which item gets the half price if the two cost different amounts?
The calculator above prices identical items: the case the offer’s percent is exact for. Mixed-price pairs differ store by store, and the receipt is the only number that settles them.
Is the calculator free, and does anything get uploaded?
It is free, needs no account, and runs entirely in your browser. The prices you type never leave your device.
Does this page list BOGO deals?
No. There are no deal listings, no third-party prices and no affiliate links; every number on the page is a labelled worked example. The page is the math that checks the offers other sites show you.