Warning: This post contains math. This is not a drill. For those not mathematically inclined you now have sufficient grounds (meh!) to leave us…

To do math, first we’ll need some coffee. To drink that coffee, we’ll need a vessel of some sort. Perhaps a mug.

Ah. I just burned my face. Now we’re ready for some coffee math!

Today’s lesson is that things are not always as they seem. For example, look at that beautiful assortment of bags of pre-ground coffee on the shelf. Wonderful, ain’t it?

How much are they? $7.99 a bag? $8.99 a bag? $9.95 a bag? $12.95 a bag? According to the Walmart.com website, a bag of Dunkin’ Donuts coffee (in my experience one of the most expensive) is $7.28 per bag. You’ll even get free shipping if you order $45 worth (or other stuff).

Most of the bags of coffee you see, including this bag of Dunkin’ Donuts, are 12-ounces in size. Wait? What?

Why?

Personally I think it is to make apples-to-apples comparisons in pounds more difficult. So how much is that bag of coffee per pound?

First, we calculate the price per ounce. Since “per” is another way of saying “divide by” the formula is simple:

Price ($7.28) per Ounce (12)

$7.28 divided by 12

Answer: $0.61 (61 cents per ounce)

Next, we multiply the cost per ounce by the number of ounces in a pound (16).

$0.61 cost per ounce * 16 ounces in a pound

Answer: $9.71

Aha! That coffee costs $9.71 per pound.

Why? Wouldn’t one-pound bags make a lot more logical sense? Since that’s a unit we already know and love? A unit that we’ve been raised with since the moment of our birth?

Perhaps I’m just in a black mood, but I think they like 12-ounce sizing because it makes the consumer feel the price is lower. “It’s only $7.28 a bag,” we are wont to say.

“$9.71 per pound” just doesn’t have the same ring to it. All of the sudden we’re talking upwards of a $10 note. Yikes. Consumer no buy-buy. Game over.

My wife just brought home a bag of coffee from a local shop. And guess what? It was in a one-pound bag and only $8. Now that’s refreshing. Sorry, Walmart. Your price sounds lower but it isn’t*.

* Disclaimer: Identical brands of coffee were not compared.