Cost Per Book Calculator: Library vs Amazon vs Used Books

Overview

Your effective cost per book changes dramatically depending on how many books you read and which service you use. The table below shows the actual cost per book at various reading levels for the major options in 2025:

Audiobooks have become the fastest-growing reading format in the U

Audiobooks have become the fastest-growing reading format in the U.S., but they can also be the most expensive. Here is how costs compare across major audiobook sources:

Libby App

Kindle Unlimited (KU) is often marketed as the best deal for ebook readers. At $11.99 per month, it provides unlimited access to over 4 million titles. But how does it compare to a library card's free ebook access via Libby?

Calculator Details

• No waitlists — any KU title is available instantly.
• Seamless integration with the Kindle ecosystem.
• A large self-published and indie title catalog not found in libraries.
• Some popular series and romance/thriller titles have strong KU representation.
• Works on all Kindle devices and apps without needing a separate library card.

Calculator Details

• Completely free — $0 cost versus $144 per year for KU.
• Access to major publisher titles often not available on KU (Big Five publishers largely opt out of KU).
• Ebooks can be sent directly to your Kindle app or device.
• Same titles available from multiple formats (ebook, audiobook, large print).
• Reading on Libby counts toward your library's circulation statistics, which helps justify library funding.

eBooks & Audiobooks (Libby)

For readers who primarily read bestsellers and mainstream fiction, library ebooks via Libby provide superior access to Big Five publisher titles — the blockbuster novels and nonfiction that dominate bestseller lists. These titles are rarely on Kindle Unlimited, which has a larger focus on self-published authors.

For readers who love self-published romance, thriller, or genre fiction in high volume, Kindle Unlimited may have more titles in those niches. But even in this case, the $144 annual cost of KU is a real expense versus $0 for the library.

Overview

Understanding the per-book cost of each reading option requires accounting for both per-title costs and subscription fees. Here is how to calculate your true cost per book for subscription services:

KU costs $11

KU costs $11.99/month or $143.88/year. Your cost per book depends entirely on usage: read 1 book/month = $11.99/book; read 4 books/month = $3.00/book; read 10 books/month = $1.20/book. The subscription only becomes competitive with used book prices if you read 6+ ebooks per month — and even then, library ebooks remain free.

eBooks & Audiobooks (Libby)

The standard Audible plan gives 1 credit per month for $14.95. Each additional credit costs $14.95. If you listen to 2 audiobooks per month, your cost is $29.90/month ($358.80/year). Library audiobooks via Libby and Hoopla are $0/month. Annual savings for a 2-audiobook/month listener: $358.80.

Access & Membership

Amazon Prime membership ($139/year) does not include free Kindle ebooks or print books. Prime Reading gives access to a limited rotating selection, not the full Kindle catalog. Prime's book-related benefit is primarily free shipping on physical book purchases — it reduces shipping costs but does not eliminate the per-book purchase price.

Overview

Book prices have increased faster than general inflation in recent years. According to Publishers Weekly pricing data:

• The average hardcover price increased from $26.50 in 2018 to $34.00 in 2024, a 28% increase.
• Trade paperback prices rose from $15.99 in 2018 to $19.99 in 2024, a 25% increase.
• Ebook prices rose from $8.99 to $12.99 average over the same period, a 44% increase.
• Meanwhile, library cards remain free for residents in nearly all U.S. public library systems.

As book prices continue to rise, the financial advantage of library borrowing grows every year. The reader who would have saved $300 per year borrowing instead of buying in 2018 may now save $400+ per year for the same reading volume.

Overview

Another way to compare reading costs is by calculating cost per hour of entertainment. The average reader reads a 300-page novel in approximately 5 hours. Here is the cost per hour of reading entertainment by source:

At $0 per hour, library reading is among the cheapest forms of entertainment available — cheaper per hour than Netflix, Spotify, video games, cinema, or virtually any other leisure activity.