Black Friday Sale Calculator

Black Friday is another uniquely American tradition that arose as many Americans have the day off work following the national Thanksgiving holiday, which about a month before Christmas, provides an opportunity to shop for gifts for that upcoming holiday.

With so many shoppers hitting their stores, many retailers looking to claim a larger share of all the cash that will be spent on Black Friday will offer special discounts to their customers, which raises an obvious question. Are their special sale prices worth the hassle of shopping at their stores?

Hanna Pamula built a tool to find out, which Lifehacker profiled earlier this month:

It certainly feels like everything is on sale all the time these days. But not all sales are created equal. It’s especially important to recognize this during the holidays, when shopping holidays feature complex discount schemes that sometimes carry equally complex limitations.

If mental math isn’t your strong suit, check out the Black Friday Calculator. “A lot of these seemingly genuine sales are often math traps,” said Hanna Pamula, a Ph.D. student in Poland who built it for The Omni Calculator Project. She includes nine different discount scenarios —percent off, buy-one-get-one, and a discount for buying multiple items, to name a few—to help you determine whether a discount is worth your time and money.

We took the tool for a test drive, and so can you, since we’ve embedded it below. If you’re accessing this article on a site that republishes our RSS news feed, please click through to our site to access a working version.

Overall, we would describe the tool as a fun personal finance application. Since it covers a number of different kinds of promotions that retailers offer, from the simple “X% off” sale to “Buy one, get Y% off a second one” to more complicated (“Get an additional W% off our Z%-off sale price”) promotions, it will be useful in evaluating many of kinds of discounts you will inevitably encounter while shopping.

On that latter count, it can help you compare competing sale prices, letting you know which retailer’s promotion delivers the biggest discount.

One thing we found was a bit of a hassle is the default setting for sales tax, which we would argue should be set to “No” rather than “Yes” for American shoppers, since most sale prices in the U.S. do not roll in the multiple levels of sales taxes that apply in the various jurisdictions that impose them across the nation. That’s less a concern for other countries that impose national value-added taxes on sale transactions, but for Americans, it will add a couple of steps between data entry and results.

The Omni Calculator project is a site that features several hundred calculators with tools for doing math that applies across a wide variety of fields and applications. We’ve been in the online tool building business for a long time, where we’re always happy to find new resources that online applications easier. If things slow down enough for you this Black Friday weekend, do check out their other tools!

Image credit: Artem Beliaikin