How many books is a lot of books? How many is too many?

As they say, one man’s collection is another man’s hoarded fire hazard, but reading this story—of a fancy Philadelphia townhouse stuffed to the rafters with 100,000 books—had me wondering where, exactly, that line is.

According to the Philadelphia Inquirer:

[Estate sales expert] John Romani encountered an enigma recently when he was hired to handle the estate of the late attorney Bill Roberts, whose private literary collection— estimated to be at more than 100,000 books—covered every room in his Rittenhouse Square townhouse and every topic imaginable, from poetry to paleobotany.

I’ve worked in multiple bookstores (and have moved too many books, too many times) so I understand that 100,000 books is, indeed, a lot of books. But how does that compare to your average corner bookstore, or your big old boxstore, or your little town library, or the largest library in the world?

For answers to these important questions I did what any literary blogger would do, I turned to the internet (what’s left of it) where I immediately found a great Tumblr post from way back in 2016, in which Rebecca Fitting, co-founder and book buyer at Brooklyn’s Greenlight Bookstore answers the question “How many books does it take to open a bookstore?” Her answer, as it related to the opening of a second store (now closed) in Prospect Lefferts-Gardens:

Here’s the big reveal on the stats:
Individual titles: 7,248
Total units: 11,305

Compared to the established store in Fort Greene where they “…carry approximately 10,000-12,000 titles depending on the time of year.”

For those of you who’ve never been, Greenlight in Fort Greene is kind of the Platonic ideal of a neighborhood bookstore, size- and curation-wise: it’s big enough to have that new book you just read about in Bookforum, but not so big that it doesn’t have a thoughtfully curated vibe.

So how does that compare, say, to a Barnes and Noble? The answer to this was pretty easy to find, right there on the Barnes and Noble website: “We stock over 100,000 unique book titles in our stores and over 1 million unique titles in our warehouse.”

This, obviously, puts into perspective the dude with 100,000 books in his townhouse (and has me leaning closer to hoarder than collector).

But what about the largest bookstores in the world?

For years, Powell’s in Portland has been claiming to be the “largest new and used bookstore in the world” with over a million books, and sure, that’s a lot, but just today a new bookstore in China has opened, becoming the world’s largest at 700,000 square feet. As of now, though, Shenzhen’s “Eye of the Bay Area” store only carries 300,000 books, so I guess the unofficial title still belongs to Powell’s.

And libraries? This one’s easier to answer. According to a 2013 library survey by the Institute of Museum and Library services, the average American library carries 116,482 books (including e-versions and audiobooks). The Library of Congress (at least until this year) has over 41 million titles, which is a lot of books! And makes it the largest library in the world.

And now, based on the numbers above, I’m actually going to answer the question posed by the headline: 100,000 books is a lot of books for one person to have and is DEFINITELY too many; at the lower end, the cut-off number for any individual reader to claim they have “a lot of books” is 1,000—not enough to open a bookstore, but enough to line a couple rooms in a house.

And to be honest, you don’t actually even need that many in, unless you’re filling an inner emotional void… just go to the library.