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Calculations Behind The Practicality Of Girl Math

This article is written by a student writer from the Her Campus at UCLA chapter.

Say you’re at Anderson Cafe and get a venti iced chai, but only drink half of it before you throw it away. You don’t feel bad because it was basically free with the swipe: girl math. Or when you’re out shopping with your friends and buy a pair of $120 Lululemon pants with $110 cash, so the pants actually just cost $10: girl math. 

The concept of ‘girl math’ has been spreading across Tiktok like wildfire. Some say it’s a totally valid way of managing and justifying your spending, while others say it’s complete nonsense. If you’re new to the trend, girl math is just a process (typically among women) of justifying how we spend our money and what our actual costs really are. The most common form of girl math is making returns where the reimbursement goes back into your account meaning that you made money. Another is buying something with cash, so when the balance in your account stays the same, there is technically no cost. 

When thinking of girl math from an economic standpoint it’s really just a combo of three basic principles. The first is sunk cost which in girl terms just means “If I return my $20 Brandy top and get a $15 top with a $5 headband I got two new things for free”. Okay, but in all seriousness, sunk cost is when money’s been spent and won’t be recovered in the future. I feel like this is definitely my favorite way of girl math-ing since it kind of follows the idea that if it leaves my account, that’s what’s been spent. Let’s just say cash is a girl’s best friend in these cases!

Second is cost-per-wear, which in simple math is the price of the purchase divided by the times that you’ll use it. See, when I was out shopping last winter at Aritzia I just NEEDED a SuperPuff jacket. I was going to go on a cold and snowy trip so I knew I was going to wear it a ton, but also it’s great quality so in my brain it’s going to last forever. From this I used my economic thinking to estimate that I’d wear the jacket at least 20 times a year for its potential product lifetime of 10 years (since it’s like really high quality). So I took the $375 price tag and divided it by 200 wears, so really it’s only about $1.88 per wear! When you have a lower cost-per-wear, in girl math that just means that you got a better deal that couldn’t be passed up. 

The final step in girl math is prospective cost. Prospective cost is seen as taking a chance on something that won’t be available later, or avoiding future costs if you take action sooner. With Black Friday right around the corner, a lot of prospective costs will be going on. During big sales like these, we feel the need to take advantage of the really good deals that are right in front of us instead of paying full price later on. I know that I’ll be evaluating the prospective cost of Black Bough bikinis this Black Friday since A) it’s bikini off-season and B) it’s at an amazing discounted rate that won’t be available until next year!

So, is girl math good? Well, it’s not as simple as a yes or no answer since there are plenty of pros and cons. Some of the most evident pros of girl math are that the phenomena empowers women in making financial decisions, lets us evaluate the impact of our spending, teaches us about navigating investments and displays an improved quality of life. On the other hand some cons are that people tend to spend more than they can afford, “long-term investments” aren’t taken care of and actually have a shorter product lifespan, and it makes women appear irresponsible or financially illiterate.

Even though women apply these simple economic principles to justify their purchases, why is girl math deemed as negative while finance bros and ‘boy math’ are seen as positive things? I guess that’s for the future of spending to tell. But for now, girl math is just a fun way to explain where our money is going while still being financially responsible!

Hannah is a second-year Economics and Political Science major at UCLA, from Yuba City, California. She enjoys writing about a variety of topics from finance to up-and-coming trends! In her free time she loves baking, going to the beach, exploring the coffee shops of LA, and playing tennis.