July 19^th, 2007

My wife winces every time the shopping cart swings into the supermarket aisle containing toilet paper. I am quite obsessed with the idea that paper companies are slowly-but-surely ripping us off. In a previous rant on this subject I named some of the techniques that I thought they were employing to make us pay more for less of their product, including:

• shrinking sheet count
• shrinking sheet size
• puffy rolls to appear larger
• larger center tube
• deceptive terminology (e.g., "double roll")
• deceptive ply count

Then I finished my ruminations with this:

I imagine that if I were to bring a calculator and figure out the exact cost per metre of all the toilet paper, I would discover that none of them is particularly better than the others. But maybe I'll try that anyway some time.

Well, the time has come. I came up with two formulas you can use to determine what is the best price for toilet paper.

Simplified formula

I found the easiest way to figure out the value of the toilet paper in a package is to calculate the number of sheets per dollar:

My wife and I bought some toilet paper the other night, and I thought we were getting a pretty good deal. Let's look at the numbers. 396 sheets per roll in a package of eight rolls. We paid $6.99 per package. So, plugging those numbers into the above formula, here's what I got:

Hmm ... although it's an easy enough number to calculate, making sense out of it is a little harder, isn't it? I mean, what does 453.2 sheets/dollar tell me? By itself, it means nothing. So, for comparison, I looked at another package and noted that each roll had only 200 sheets on it (despite being called a "double roll"—a completely meaningless term, anyhow) and a package of 12 was $8.89. Let's look at those numbers:

Wow, so it looks as though we got a pretty good deal with our 453.2 sheets/dollar, didn't we?

Complex formula

But, alas, it isn't quite so simple. There are some other considerations.

Sheet density

One thing to think about is the sheet density, which paper companies are happy to tell you about on their package as plies. 2-ply seems to be the most common, but I saw some 1-ply toilet paper and some 3-ply toilet paper. And, to further muddy the waters, a 2-ply sheet of toilet paper is not twice as thick or dense as a 1-ply sheet. It appears to be only marginally thicker. And a 3-ply sheet appears only about 50% thicker than a 1-ply sheet, not triple, as the name might suggest. So how to factor this into the equation? I settled on a somewhat complicated formula that assumes 2-ply as a "standard" size: I add 2 to the number of plies, take the square-root of that, then divide by two. This returns a value of 1 for 2-ply, 0.87 for 1-ply, 1.12 for 3-ply, 1.22 for 4-ply, etc. (I'd like to point out this is a formula derived to match my observations only.)

Sheet size

Another consideration is the size of the sheets. Again, I had to come up with a standard for sheet size and noticed that they all were more-or-less 100 square centimetres in size. So I added a height and width component, with 100 cm² as the standard.

Here is the adjusted equation:

OK, so using this formula I can now calculate what I think is a very accurate adjusted number of sheets per dollar, and from that I can figure out which roll is the best deal. Let's go back to our purchase: 396 sheets per roll, eight rolls in a package costing $6.99, and they were 2-ply sheets with dimensions 10.1cm by 9.9cm, and plug those numbers into my equation:

And let's compare it with another package sitting next to it that had 3-ply sheets, but a lower sheet count and a higher price:

Well, okay, so our purchase still looks pretty good. But then I went through and did a whole bunch of other products. Here are the numbers:

Brand and type	Sheets/roll	Rolls/pack	Cost/pack	Plies	Width(cm)	Height(cm)	Value
Generic	198	4	$2.49	2	10.1	9.9	318.0
Western Family Premium Soft (1)	352	12	$7.99	2	10.1	9.9	528.6
Western Family Premium Soft (2)	396	8	$6.99	2	10.1	9.9	453.2
Western Family Premium Soft (3)	352	8	$6.99	2	10.1	9.9	402.8
Western Family Ultra	264	12	$6.79	3	10.1	9.9	521.6
Kleenex Cottonelle Double	200	12	$6.99	2	10.1	9.9	343.3
Kleenex Cottonelle Single	176	24	$6.99	1	10.1	9.9	523.3
Purex Double	352	8	$6.49	2	10.1	9.9	433.9
Purex (Plain)	176	24	$8.99	2	10.1	9.9	469.8
Purex Ultra	264	12	$8.99	3	10.1	9.9	393.9
Charmin Extra Strong	200	12	$8.89	2	10.1	10.0	272.7
Charmin Ultra Soft	200	12	$8.89	2	10.1	10.0	272.7
Charmin	200	16	$11.49	2	10.1	10.0	281.3

*Note: All prices are regular (non-sale) prices recorded at Save-On-Foods in Burnaby, BC, July 18th, 2007.

My guess about which of the packages of toilet paper had the best value (453.2 sheets/dollar) was not right. It was a pretty good guess, and I only got slightly burned, but there were better-valued packages on the shelf that I passed over. It's tricky to make an educated consumer decision, isn't it?

Conclusions

Anyhow, now that I have all the brands on more-or-less even footing, I can draw some conclusions from the comparison data:

1. Generally speaking, the more rolls per package, the better the value. That shouldn't be a surprise at all, since our entire Western Empire is based on that principle.
2. Another thing you can see is that large North-America-wide advertised big name brands offer less value than smaller name brands. Again, this shouldn't come as too much of a surprise, considering the fact that the big names have to pay for all that splashy expensive advertising somehow, don't they?

I'm glad I did this rather tedious work on toilet paper value. It has really helped to ease my anxiety about being "ripped off by the big paper companies". I mean, though there is variation, it is along predictable lines. If you want to save money, buy toilet paper that is on sale, and if none of it is on sale, buy larger packages to maximize your value. You can also bring a calculator shopping and use either of my formulas to figure out the best deal ... I guess it depends on how much your time is worth.

What will be more interesting is to compare the values I've captured in the table above with numbers a year, two years, five years, etc. from now ... though I think that might follow predictable lines too :-)

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