How many books fit on a bookshelf?

Any bookshelf, any books. Enter the usable shelf width and how many rows you'll fill, and get the book count — measured, not guessed.

Enter your setup

Your bookshelf

Usable width per shelf

Shelf rows

rows

Your books

Average book thickness

Measure a 20-book stack and divide by 20.

Books you own

books

Use positive measurements and valid numbers.

BOOKS · SHELF

Estimated total capacity

–

yours

Do you need more shelving?

Adjustable bookendsAmazon Extra bookcaseAmazon

Hand-picked for this exact result — no generic lists.

Shelf width is measured inside the uprights — not the furniture's outside width.

Measure a real 20-book stack.
Paperbacks and hardcovers differ wildly; a measured average beats any guess.
Leave a finger of air.
Books packed drum-tight are miserable to pull out.
Count only fillable rows.
Decor, frames and leaning stacks don't hold books — subtract those rows.
Check the weight.
A full shelf of hardcovers is heavy. Respect the shelf's load limit.

One concrete case, with the assumptions spelled out.

At 3 cm per book, one shelf holds about 30 books. Five rows give 150 books.

ƒ(x)per shelf = floor(usable width ÷ average thickness)