The trend of Girl Measuring everything is a little weird, but it makes sense. Whether you’re debating if a bowl of popcorn counts as Girl Dinner or justifying buying a dress based purely on its resale value, the math is mathing. And truly, no one understands Girl Math more than a beauty aficionado.
Beyoncé once said, “It should cost a billion to look this good,” and sometimes walking through a Sephora can feel that way. Between the cost of maintenance appointments — hair, facials, and nails — and the upkeep purchases — skincare, haircare and everything in between, Beauty Girl Math is a master class in return on investment. People will spend a lot of money on self-care — this isn’t about vanity.
So, how exactly does Beauty Girl Math work? Personally, any time I reuse my hair extensions, I’ve saved money. A $500 human hair wig is less expensive than six $60 wigs. Purchasing a $40 moisturizer at Sephora or Ulta is less costly than a $40 moisturizer from a drugstore. A viral example of Beauty Girl Math is the woman from TikTok who went to Turkey for hair extensions and spent $1,500 on the entire trip. (She was quoted $4,450 by her regular salon in the US, almost $3K in savings.) It's a hair vacation — and the ultimate in Girl Math. If she and I are Beauty Girl Math-ing, we must all be, right? To answer that question, I spoke to some of the beauty industry’s biggest names to see how they apply Beauty Girl Math to their own lives.
Being a Smart Shopper = Beauty Girl Math
Beauty Girl Math is a way of life, but it’s not unattainable. Remember when we were all obsessed with Extreme Couponing? That’s kind of what Beauty Girl Math is — finding the best and most effective way to get what you want and for the least amount of money. Multipurpose products are the ultimate return on investment. “Buying multipurpose products is my go-to. I don't want to spend money on a bunch of products when I can buy one product for multiple purposes and keep my makeup routine clean and edited,” says Kirsten Carriol, founder and CEO of Lanolips. “I can mentally divide the cost of the product by how many different ‘off label’ ways I dream up to put it to use.” Whether it’s a $65 10-pan palette with multiple shades that you can use to create your entire face including blush and lip color, a 10-in-one leave-in hair treatment or a lip balm that doubles up as a cuticle moisturizer, it all adds up in the end.
Refillable products are always a great example of the trend, especially if the refill is on a subscription model that applies a discount. “If I buy something refillable, the cost of the original purchase and the original packaging feels like nothing — since it averages down to cents per use if you keep it forever,” founder of Seadrop Skincare, Serena Advani, says. But double-check before you make the pledge. You don’t want to commit to a refillable product only to realize you’re paying for more packaging over time.
Beauty Girl Math is how we afford beauty treatments, duh.
Tara Adashev, advanced practice registered nurse at Neinstein Plastic Surgery, prioritizes laser treatments, peels, and injectables when it comes to her beauty splurges. “I always budget quarterly for skincare spending over fancy dinners and lattes. I would rather see my money on my face than in a tossed Starbucks cup. For me, sometimes you just need La Mer over the latte.”
Beauty Girl Math is best applied when it comes to cost spent vs. time saved. The convenience of press-on nails embodies the rule, saving you both time and money in the nail salon. Joyce de Lemos, Chief Product Officer of Dieux Skin, says it perfectly: “Girl Math is getting my eyelashes done for $120 because it shaves off 15 minutes of doing eye makeup in the morning. That means less rushing, which means less stress, which means less therapy.” Cost per use is king. Or queen, I suppose.
Justine Marjan, Celebrity Hairstylist and Great Lengths USA Brand Ambassador, shared that her hair extensions are the key to Beauty Girl Math: “When I put in my extensions, I save money and time because I don’t have to spend all day at the salon getting my color done or a haircut for the next five months. It’s also an investment because my hair will already be styled when I wake up in the morning, meaning more time for work, travel, or fun.”