Subscription fees for Netflix, Hulu, and others added up to nearly $700 a year for author Elyssa Kirkham's family.

She canceled those subscriptions and switched to a library card with which she could get the same entertainment.

She used that saved money to make $57 of extra student loan payments per month.

"All the thoughts and dreams of people throughout history, and all you need's this little card to borrow 'em for free!"

Other children of the '90s might recognize this lyric from the classic tune "Library Card," rapped by the cast of the cartoon show Arthur. It's a silly song, but it's a solid reminder that libraries can be amazing sources of entertainment and education. And unlike a credit or debit card, swiping a library card doesn't cost a thing.

But exactly how much can you save by choosing your library card over a credit or debit card?

I recently overhauled my budget, and in the process, I decided to put my local library to the test. The exercise saved me nearly $700 per year in dodged subscription costs—money I now use to make $57 of extra student loan payments per month. Here's how it worked.

Cutting back on entertainment subscriptions

I'm decent at setting and following a budget. But there I was, facing another month where my family netted $0.

Specifically, I was bugged by how many frivolous entertainment subscriptions we had. I subscribed to a video streaming service here; my husband signed up for a premium account there. Although each account seemed affordable or even cheap, they added up.

Upon review, I realized that in the past year or two, we've paid for a number of entertainment subscriptions:

$12 per month for Hulu Plus

$9 per month for Netflix

$15 per month for Audible

$11 per month for online newspapers and magazines

$10 per month for Spotify Premium

We'd mindlessly signed on for $57 per month in subscription fees that added up to $684 per year.

Don't get me wrong, I think entertainment subscriptions can be a savings-savvy alternative to pricier options like paying for cable or seeing movies in theaters. The problem wasn't the subscriptions themselves—it was the mindless spending they reflected.

Finding free entertainment at my local library

I thought I could find better uses for that cash if I canceled those services. But I didn't love the idea of quitting cold turkey.

My Audible subscription caught my eye first. It cost me $15 per month. But I already used the OverDrive app, available through my local library, to request, check out, and listen to audiobooks for free. So I killed my Audible subscription and gained an extra $15 per month right there.

I wondered if I could replicate those results for other subscriptions. I dove into my library's digital catalog and quickly found out.

Magazines

My library partners with RBdigital (formerly Zinio) to offer a range of digital magazines. I used the service to replace a subscription to ESPN The Magazine ($2.50 per month) and found lots of other reading material worth browsing.

Newspapers

The New York Times digital pass that's part of my library membership grants me access to New York Times apps and unlimited articles at NYTimes.com. That meant I could cut $8 per month from my budget and still support an outlet I love.

PressReader is another decent replacement for subscriptions to periodicals, and I can access it for free through my library.

TV and movies

I took the plunge and ended up canceling my $9-per-month Netflix membership of more than eight years. Now, my family accesses documentaries and movies through Kanopy and OverDrive, thanks to our library accounts.

For my 4-year-old daughter, Nickelodeon shows on Hoopla are all the rage, so I was able to cancel my subscription for Hulu Plus and save $12 per month.

Music

My library card granted me access to music streaming and downloads through Hoopla and Freegal. Bye-bye, $8 Spotify Premium fee.

In all, I found $57 worth of monthly fees to cut from our budget. My family easily saves $684 per year while enjoying much of the same entertainment and content we've always loved.

5 tips for getting the most out of your library card

Like most budgeting decisions, trading in your subscriptions doesn't come without sacrifice. I've learned a few tricks along the way to make the most of my library card.

Don't forget analog entertainment

My main goal in cutting costs was replacing my entertainment subscriptions. However, I can't always find a decent digital replacement. In many cases, I request a physical copy of the book, movie, TV show, or music album and pick it up during my next library visit.

Get comfortable with a little delay and inconvenience

A huge benefit of paid subscriptions is instant, convenient access to any content you want on a particular platform.

With library services, there might be a limit on how much content you can check out or access at a time. You might get put on a waiting list for a book or movie as well. It can be an annoying adjustment, but remember that you're saving money.

Find other cost-saving materials and services

Some library districts offer free tutoring services as well as resources to help students study for the SAT or graduate placement exams.

I also found out that my library card gives me access to Lynda.com's online educational training. This allowed us to replace a $29-per-month membership my husband had been using to brush up on his web development skills and brought our annual savings up to $713.

Take a look at some of the streaming services available with your library card. You might have access to free workout videos, which could replace a gym membership.

Watch out for late fees

Of course, it's important to watch out for library card fees. One of the reasons I prefer digital library content is that it's automatically returned when the time is up, so I never get a late fee.

But I've racked up some significant late fees and replacement fines for physical items I didn't return to the library in a timely manner. If you're not careful, your library fine could wind up in collections and damage your credit.

If you do check out physical copies, get in the habit of keeping track of them and making regular trips to return them on time.

Know when to keep a subscription

Some library districts are well-funded and have great selections. Others, not so much. If your library's pickings are slim, you might decide you'd rather keep your paid subscriptions. Even a big library district with awesome options won't be able to offer you everything you could hope for.

Although my library offers a robust selection of services, I decided to keep a few subscriptions. My Amazon Prime membership offers tremendous value for its $99-per-year price, including access to free shipping and streaming services for music, movies, and TV shows. My husband loves podcasts and decided he wanted to keep his $5-per-month Stitcher subscription to support the platform.

Take the challenge to turn to your library card before your credit card, and you might be surprised by the savings. And remember: When you cut out monthly subscriptions, you're saving money not just once, but also every month thereafter.

You can take your new cash flow even further by using it to pay down credit card debt—a smart option, considering the average credit cardholder owes over $4,000. Or you could look for other ways to build lasting wealth, such as saving for retirement or building a side hustle. Find more ideas on how to save money without depriving yourself at Credit.com.