No wonder shaving your head like Kristen Stewart is all the buzz  – -shorn women say the look trims hundreds of dollars in salon visits and grooming products.

The average American woman drops $1,800 in salons a year for haircuts, blowouts and mani-pedis, according to recent data from Square mobile payment company, with New Yorkers spending $73 per cut and tipping another 20%. 

A 2010 British survey by TRESemmé puts the numbers even higher, reporting the average woman spends a hair-raising $50,000 on her tresses over her lifetime, including $520 a year on haircuts, $160 on shampoos and conditioners, and $120 on styling products. Those who dye their hair drop another $330 a year.  

So why not cut out those expenses by cutting off the source?

New Jersey actress Stephanie Crousillat, 27, is no stranger to spending a pretty penny on her unwieldy waves.  “Just a six-ounce bottle of cream from Hairstory was $40 bucks!” she said.

So Crousillat, 27  was thrilled when her witchy role in “Sleep No More” at the McKittrick Hotel theater in Midtown called for her to go bald. Besides shelling out hundreds on products to control her curls, she was also spending at least 30 minutes a day styling her hair just right.

“I was a perfectionist, so it took up a lot of time,” she said. “Now it takes 10 minutes to get ready. Having no hair is super liberating and convenient. I buzz it myself, shower, rub on a little coconut oil, and that’s it.”

Manhattan veterinary technician Melissa Berry, 39, guesses she’s dropping $240 a year on hair care products alone, with another few hundred cutting her curly hair two or three times a year. She longs for the simpler time when she shaved her head at 26.

“Removing my hair definitely made getting ready/showering take 10 minutes, and no products needed,” she said, “which is huge for me, since I have curly, frizzy hair that requires at least two to three different products to keep it under control.”

That’s good news for Stewart, 26, who debuted her buzzworthy new platinum crop at the premiere for her new movie, “Personal Shopper.” Celebrity stylist Oscar Blandi notes, getting an actress’s coif red carpet ready can take an hour or more.

“This saves a tremendous amount of time. Shower for five or 10 minutes, and boom! You’re out. Moisturize your scalp and you’re good to go. You don’t have to do anything,” he said. “It’s very bold of her. I think it looks great.”

Model Amber Rose has rocked a similar look since she was a teen, and noted in her in 2015 book, “How to Be a Bad Bitch” that, “Finding my look had helped me find myself, and that set me free. I got all of that from a $10 buzz at the barbershop, the cheapest, easiest haircut there is.”

She’s also raved, “The best is that once you cut and bleach it, you have a good three days of waking up and literally your hair being done.”

Even Oscar-winning actress Cate Blanchett has occasionally lopped off her signature blond locks. “Shaving off my hair is so liberating. I had to do it once for a film role, but I’ve done it periodically too,” she told the Daily Telegraph.

That’s one reason Ann-Michele Corbi Potvin, a 43-year-old counselor, misses the buzzcut she rocked in 2000 as part of her “radical feminist exploration.”  

“I literally had hair down to my butt for most of my life until that point,” she said, remembering it took at least 90 minutes to get ready for school each day. “When I shaved my head I could be ready in five to 10 minutes.”

Now she spends $140 per salon session to cut and color her bob. “When my head was shaved I could just wash my head with moisturizing bar soap. And I don’t think I’ve ever felt more beautiful than I did at that stage in my life,” she said. “This is making me want to shave my head again!”