Don't look at the number of rolls, or the number of sheets, or the size—
just hone in on the square feet total area.
(1419 square feet for this package)
It is amazing how widely the price of toilet paper varies, and it doesn't always have a lot to do with quality. I always felt like I was shooting in the dark when I bought toilet paper, until we figured out a way to determine a comparison price quickly, without a caluclator!
To figure out the best price: just look at the total number of square feet in the package and move the decimal place up 2 spaces. So, if the package says "total area 1419 square feet", mentally move the decimal place up 2 spaces to 14.19 and add the dollar sign = $14.19. A great price for toilet paper is .01 per square foot of toilet paper. So, $14.19 is the price this package (above) would be if it was .01 cent per square foot.
Now, compare the price of the toilet paper to the number you calculated in your head. If the sale price on this toilet paper was $14.19, it would be a nice bargain (at .01 cents per square foot). In this case, the price was even lower: just $9.99, so I got a real deal, and I bought a lot!
One ply or 2 ply? It doesn't matter, as ultimately you use about the same square footage at each application. (Did I say that delicately enough?) With 1 ply, you just have to unroll more and double it up, but you still use basically the same amount.
Need another practice problem?
Well, I just got home from shopping and I saw a pack of toilet paper on sale at the grocery store on a big end cap with a sign that said, "WOW! SALE! $8.88". That caught my eye, so I took a quick glance at the total square feet in the package. To qualify as a good sale, the package would have to contain 888 square feet (or .01 cent per square feet). Don't pay any attention to the other numbers (sheets, size, etc.). The package stated that there was just 651 square feet total area. No matter the "wow, sale" sign, it wasn't a wow deal. At just 651 square feet, it would have had to be priced at less than $6.51 to be a good buy.
Once you get the hang of it, you'll be surprised at how wildly erratic the pricing on toilet paper is. Maybe it is because consumers can't figure it out easily and just buy whatever looks like a deal, so they can take wide leeway. Even the little shelf label tags that figure it out for you at some grocery stores don't seem to help, as they often calculate the price per roll—but every roll is different!
Now that you know an easy way to make sense of the price, save some money and stock up!