Multipacks, BOGO & Multi-Buy Deals: How to Compare Them
A bundle offer has two parts: the total amount you pay and the total product you take home. The difficult part is often translating the promotion into those two numbers. Once you do, a case, a “3 for” offer, and a buy-one-get-one promotion can all be compared using the same unit-price calculation.
The examples below assume you qualify for the stated promotion and buy the required quantity. They use illustrative prices. Read the actual offer's conditions before calculating: the number of items required, eligible sizes, coupon limits, and which item receives a discount can affect the total.
Describe the whole offer in the calculator
Total quantity = number of items in pack × quantity per item
For a $9 case containing 12 cans of 12 fluid ounces each, the total volume is 12 × 12 = 144 fl oz. Its unit price is $9 ÷ 144 = $0.0625 per fl oz. That is the underlying arithmetic; the calculator's displayed unit price rounds upward to a cent, as explained in our methodology.
In Compare Deals, enter 9 under “Price,” enable “This is a multipack,” enter 12 under “Number of items in pack,” and enter 12 under “Amount in Unit.” Choose “fl oz” for the Unit. Price always describes the entire offer, while Amount in Unit describes one can.
You can also enter total volume directly: Price 9, Amount 144, Unit fl oz, with the multipack option off. Both approaches describe the same purchase. Do not enter 144 as the amount per can and multiply by 12 again.
Compare “2 for $10” with “3 for $14”
If every bottle contains 500 mL, the first offer buys 1,000 mL for $10. That is $10 per liter. The second buys 1,500 mL for $14, or about $9.33 per liter before display rounding. The second offer is cheaper per volume, although it requires spending $4 more and taking another bottle home.
For Deal A, enter Price 10, enable the multipack option, enter 2 items and 500 mL per item. For Deal B, enter Price 14, 3 items, and 500 mL per item. The same quantity per bottle makes the comparison straightforward.
Now imagine that the three bottles are only 400 mL each. Their total volume becomes 1,200 mL, so $14 ÷ 1.2 L is about $11.67 per liter. The “3 for $14” offer now loses to the two 500 mL bottles for $10. Price per bottle alone would hide that reversal.
Check whether you must buy the advertised quantity. If one bottle from the two-for offer is available for $5, you may be able to get its unit price without buying two. If the discount applies only when buying two, use the required bundle's total price and quantity.
Buy One Get One Free
Suppose an eligible 16-ounce jar costs $4, and buying one gives you a second identical jar free. You pay $4 for 32 ounces. The unit price is $0.125 per ounce. Enter Price 4, 2 items in pack, and 16 oz per item.
For two identical items at the same regular price, this halves the regular unit cost. It does not prove that the offer beats every other brand. A competing 32-ounce jar at $3.84 costs $0.12 per ounce and is cheaper than the BOGO pair.
Use the Buy X Get Y Calculator when you know the item price and how many items you need. It applies only complete promotion groups and compares the result with another per-item price. If the offer allows different eligible sizes or prices, calculate the actual checkout total and combined contents instead; do not assume the free item is whichever one you prefer.
Buy One Get One 50% Off
With two identical $4 jars, the first costs $4 and the second costs $2. The pair costs $6, not $4. Both together normally cost $8, so the overall discount is $2 ÷ $8 = 25%. “50% off” describes the second jar, not the complete purchase.
If each jar holds 16 ounces, the unit price is $6 ÷ 32 = $0.1875 per ounce. In the Buy X Get Y Calculator, enter $4 per item, Buy 1, Get 1, and 50% off. A regular 32-ounce jar priced at $5.76 costs $0.18 per ounce, so it beats this promotion on quantity value.
For differently priced products, work out which receives the half-price discount. For example, if the offer discounts the cheaper of a $6 item and a $4 item, the total is $6 + $2 = $8. The equal-price 25% shortcut would not correctly describe that pair.
Buy 2 Get 1 Free
Three identical 10-ounce packages priced at $3 each cost $6 when one is free. You receive 30 ounces, making the unit price $0.20 per ounce. Enter Price 6, 3 items in pack, and 10 oz per item.
Compared with paying $9 for all three, the discount is one-third of the regular total. The Buy X Get Y Calculator can also price four or five requested packages correctly: one complete group receives the discount, while the extra packages remain full price. A promotion that requires more product may have a lower unit cost without being the best fit for a small shopping trip.
Choose between cans, bottles, rolls, sheets, and pods
Count is useful when the counted objects are equivalent. A 30-pod bag for $9 costs $0.30 per pod. A two-bag bundle containing 20 pods per bag for $10 costs $0.25 per pod. For the bundle, enter 2 items in pack, 20 as Amount in Unit, and pod as Unit.
For paper, a per-sheet comparison often explains more than a per-roll comparison. Six rolls with 120 sheets each give 720 sheets. Eight rolls with 80 sheets each give 640 sheets. The package with more rolls actually has fewer sheets. At $7.20 and $6.40 respectively, both cost exactly one cent per sheet.
Sheet dimensions, thickness, and usefulness can still differ. Likewise, pods may require different doses for the same job. The calculator treats count labels as individual units; it cannot decide whether one roll, pod, or bottle provides the same usefulness as another.
Handle mixed bundles without inventing an average item
If a pack contains two 500 mL bottles and one 250 mL bottle of a comparable product, its total volume is 1,250 mL. Enter that total as Amount in Unit with the multipack option off. This avoids pretending all three bottles contain the same amount.
A bundle containing unrelated products is harder to compare meaningfully. Adding a shampoo bottle and a sponge as “two items” produces a number, but not a useful shared unit cost. Compare equivalent bundles or consider the individual products you actually need. For more on selecting a fair measure, see how to compare unit prices.