Calculate Book Spine Width
Estimate a book's spine width from its page count and paper weight, and download a cover template for an A4 book with the fold lines marked.
About This Tool
Calculate Book Spine Width estimates how thick the spine of a bound book will be from two things you enter: the number of pages and the weight of the paper. There is no file to upload.
The estimate is the number of sheets, which is half the page count, multiplied by a fixed thickness per sheet: 0.10 mm for 80 gsm paper, 0.12 mm for 100 gsm, 0.14 mm for 120 gsm and 0.18 mm for 150 gsm. A 100-page book on 80 gsm paper comes to 5.00 mm. Real paper varies and the cover is not counted, so treat the figure as a starting point and confirm it with your printer.
The tool also makes a one-page PDF template: two blank A4 panels for the covers with the spine between them, a dashed fold line on each side of the spine, and, when the spine is wider than 12 pt, your text along it. It is a guide for building the real cover in a design program, not a finished cover: it has no artwork, no bleed and no printer's marks. Everything is worked out in your browser.
How to Use
Enter the page count and the paper
Type the number of pages in the book under "Number of pages", counting both sides of every sheet. Under "Paper weight" choose 80, 100, 120 or 150 gsm. The estimate is shown above the book model.
Type the spine text
Type your title under "Title on the spine", in English or Arabic, or leave it empty. It is printed down the middle of the spine, reading from top to bottom, and only when the spine is wider than 12 pt (about 4.2 mm). A title too long for the spine is made smaller to fit.
Create the template and download
Click "Make the cover template", then "Download". The book model can be turned by dragging, but it is only an illustration. To make a template with other values, change them and click the button again.
Use Cases
Thick proposals and reports
Find out roughly how wide the spine of a bound tender or annual report will be before you start on its cover.
Theses and dissertations
Estimate the spine of an A4 thesis from its page count and paper weight, and get a sheet with the two fold lines in place.
A first check for a self-published book
Get a quick estimate while you plan the book. For the final cover, use the spine width your printing service gives you.
Frequently Asked Questions
How accurate is the spine width?
It is an estimate. The tool counts one sheet for every two pages and multiplies by a fixed thickness per sheet: 0.10 mm for 80 gsm, 0.12 mm for 100 gsm, 0.14 mm for 120 gsm and 0.18 mm for 150 gsm. Paper of the same weight differs from one make and finish to another, and the cover and glue are not counted, so confirm the figure with your printer.
Is the PDF a finished, print-ready cover?
No. It is a plain template: two blank A4 panels with the spine between them, two dashed fold lines, the spine text (on spines wider than 12 pt), and a small line of figures in the bottom-left corner. There are no flaps, no bleed, no crop or registration marks and no colour bars. The sheet is as wide as two A4 pages plus the spine, so wider than A3 by the width of the spine. Use it as a guide and build the real cover in a design program.
Can I upload my book or a cover image, or use another page size?
No. No file is uploaded or read: you enter the page count yourself, and the cover panels are always A4. There are no fields for an author, a background or a picture, and no setting for single-sided printing.