It was just about this time last year when toilet paper started flying off store shelves, leaving shoppers to buy whatever they could find. Now that it's available again with only a few stores limiting purchases, there's another question about TP: what's the best deal?

Unlike most other products, there are no industry standards when it comes to branding toilet paper. That's why you'll see words like "mega," "super mega" and "ultra" rolls advertised on the packaging.

If you've ever wondered what’s the difference, there's an online calculator just for you.

The toilet paper calculator pro uses a large database of average prices, square or sheet size, sheets per roll, and square footage to help determine which brand is the better value.

I used the calculator for the first time today in my local supermarket to see how it works. I simply entered the number of rolls in the pack along with the number of sheets per roll and the price. A 4-pack of Angel Soft Mega roll advertises each roll has 425 sheets. The 4-pack was $6 in my local store. Entering all of that information into the TP Calculator Pro, I learned that this particular 4-pack came out to about .4 of a cent, which earned it a failing grade.

I tried it using other brands and found Quilted Northern's Mega rolls along with Charmin's Super-Mega rolls all came up short (literally) in value as both earned an F, according to the calculator. The only brand earning an A+ was Scott's 1000 sheet rolls which came to .01 cents a sheet.

The calculator doesn't take into account the number of plys. Scott brand is one-ply while the others are two- and three-ply. Entering the equivalent rolls changed things substantially as most all Mega and Super Mega rolls earned an A+ rating. But seriously, how can you count 1 roll as 3 since it's three-ply? Do people really use fewer squares or sheets because the TP is thicker? Maybe.

The calculator also does not take into account comfort, absorbency, and other factors that are important to tp shoppers and users. But if you're looking to save money and get the most value from the toilet paper aisle, you might want to check out the toilet paper calculator from an unbiased toilet paper expert.