3 Reasons Why 'Girl Math' Is a Spending Trap

When Mattel released a talking Barbie doll in the early 1990s who was programmed to utter the phrase "math class is tough," there was a huge uproar -- so much so that Mattel opted to reprogram Barbie to avoid commenting on the matter. 

While it was never expressly stated that Barbie dolls are meant solely for female consumers, the reality is that little girls have always been Barbie's target audience. And consumers didn't like the implication that girls were likely to struggle with math.

But now, there's a new association between women and math that's far from favorable. It's a trend known as "girl math," and it's taken TikTok by storm.

"Girl math" refers to justifying the cost of a given item by breaking its price down on a per-use basis. There are variations on that theme, but that's the gist of it.

In a nutshell, "girl math" might tell you that if a handbag costs $365 but you plan to use it every day for a year, you're only paying $1 per day. That lower cost might make that otherwise large outlay more palatable for some consumers. 

Not only can "girl math" easily be construed as offensive, but there are some major flaws with the logic. Here are a few reasons why "girl math" is nothing more than a spending trap.

1. Just because an item is inexpensive on a per-use basis doesn't mean there's not a more economical alternative

You may be inclined to use "girl math" as justification to buy something on the pricier side. Let's say you need a new coat. That's a reasonable expense. And if you find a coat that costs $360 and you expect to use it for 120 days out of the year, you're only paying $3 per day to stay warm. That's not such an outrageous amount.

But while $3 a day may not be such a large number to wrap your head around -- after all, it may be comparable to the cost of your daily store-bought coffee -- that doesn't mean there's not a less expensive coat you can buy that will only cost you $1.50 a day. And if money is tight, you're better off buying the coat that costs less.

2. Just because you're spending minimally per use doesn't mean you can afford the item in question

Perhaps you're buying a piece of jewelry for $300. If you intend to wear it every day for the next three years, you're spending just $0.27 a day. That's a negligible amount. 

But just because your per-use cost is minimal for a given item doesn't mean you can afford that item. It may be that buying that jewelry results in a $300 credit card balance you're forced to carry forward and accrue interest on. That's not a good situation to land in.

3. You don't know how much use you'll get out of a given item until you actually own it

You might be window shopping when you spot the most beautiful pair of boots you've ever seen. Those boots might come close to costing what your monthly mortgage payment does. But you might justify that purchase by saying that if you wear them numerous times a year over the next decade, your cost per wear will be fairly small.

But affordability issues aside, the problem here is that you're making certain assumptions about your usage. You're assuming fashion won't change, your feet won't grow (if you've ever been pregnant, you know full well this is possible even in adulthood), or that the boots will be comfortable enough to get great use out of them. None of these things are guaranteed.

It's okay to splurge, but know what you're getting into

At the end of the day, the problem with "girl math" is that it has the potential to encourage people to make purchases they shouldn't, either because they can't afford them or they won't really get good value for their money. To put it another way, "girl math" is a means of dismissing guilt over buying things. But sometimes, guilty feelings pop up when you're making a purchase for good reasons.

If you see something you want to splurge on and you have savings and no debt, go for it. But don't use "girl math" to justify your purchase. Instead, tell yourself, "I like this, I can afford it, and I'm choosing to spend my money on this over something else." It's that simple. 

And if you can't afford a given item that catches your eye, save up for it. That way, you can move forward without guilt -- and without having to run calculations that break down the cost of owning that item by the minute.