Reese's Peanut Butter Cup Math

I am overly fond of Reese’s Peanut Butter Cups. It’s kind of a problem. They’re one of my weaknesses, one of the foods which cause me to lose most of my self-control: if there’s a stash of Reese's Peanut Butter Cups residing at my house, I will eat them. All of them. In one sitting (or pretty close to it).

Anyway, naturally I like to get the best deal on my peanut butter cups, so tonight when I went to the store, I studied my options. (I looked only at the regular-sized peanut butter cups, not the puny bite-sized ones: those don’t have a high enough peanut butter to chocolate ratio.) There were four different choices:

• A tray of 8 individually-wrapped peanut butter cups for $1.39
• A tray of 6 two-packs of peanut butter cups for $3.89
• A bag of 14 peanut butter cups for $2.69
• A “snack box” of 24 peanut butter cups for $4.29

I did the math, and determined the price per peanut butter cup for each option (rounded to 4 decimals):

• 8-pack: $0.1738
• 12-pack: $0.3242
• 14-pack: $0.1921
• 24-pack: $0.1788

By these calculations, it looks like the 8-pack would be the best value. However, when I looked more closely, I saw that the peanut butter cups, although all labeled as “snack size,” were not the same size at all. Some of them were 15 grams, some were 21 grams each. Here's how it broke down:

Package	Single Cup Weight (Grams)	Package Weight* (Grams)	Package Price	Price per Gram
8-pack	15	124	1.39	0.0112
12-pack	21	255	3.89	0.0153
14-pack	21	297	2.69	0.0091
24-pack	15	374	4.29	0.0115

And the winner is... the bag!

I found it interesting that in no circumstance was the "snack box" the best value.

Just for kicks, I bought both a bag and an 8-pack, so I could compare the two sizes. Here they are in their wrappings:

Opened:

With a Lego minifig for comparison:

Eaten:

I cannot yet say which tasted better. To me, they were both delicious. I will admit, however, that the 15-gram peanut butter cup did look better, but maybe that's because it was better packaged, and not knocked around as much as the one from the bag.


*The package weight is according to what was printed on the package, not according to mathematical calculations.