How do I calculate the spine width of a book?

Divide the number of interior pages by 2 to get the number of sheets, then multiply by the thickness of one sheet. For an A5 book with 60 interior pages on woodfree 90 kg paper (about 0.12 mm), that is 30 sheets × 0.12 mm = 3.6 mm. Some printers also add the cover thickness, so follow your printer's method.

What is the cover size of an A5 book in mm and px?

The cover is made as one piece: front, spine and back. For A5 (148 × 210 mm) with a 3.6 mm spine and 3 mm bleed, the width is 148 × 2 + 3.6 + 6 = 305.6 mm and the height is 210 + 6 = 216 mm, which is 4211 × 2976 px at 350 dpi. One interior page with bleed is 154 × 216 mm (2122 × 2976 px at 350 dpi).

What pixel size should B5 interior pages be?

B5 (182 × 257 mm) plus 3 mm bleed is 188 × 263 mm, which is 2591 × 3624 px at 350 dpi and 4441 × 6213 px at 600 dpi. Black-and-white comics are often made at 600 dpi and color pages at 350 dpi.

How wide must the spine be to print text on it?

It depends on the printer, but with a spine under 3 mm it is safest not to put text on it. Cutting and binding can shift by about 0.5–1 mm, so use small text for 3–5 mm and leave a little margin at both edges even at 5 mm or more.

In what order do I print the pages of a saddle-stitched zine?

For an 8-page right-to-left zine, sheet 1 has pages 1 and 8 on the front and 7 and 2 on the back, and sheet 2 has 3 and 6 on the front and 5 and 4 on the back (for left-to-right binding, left and right swap: 8 and 1, 2 and 7, 6 and 3, 4 and 5). Print on landscape paper with duplex set to “flip on short edge”, stack the sheets, fold them in half and staple along the fold. If the page count is not a multiple of 4, blank pages go before the back cover.

How thick and heavy is woodfree 70 kg or 90 kg paper?

As a guide, 70 kg is about 0.095 mm and 90 kg about 0.12 mm thick. The ream weight is the weight of 1,000 shiroku-size sheets (788 × 1091 mm); as basis weight (weight per m²), 70 kg is about 81 gsm and 90 kg about 105 gsm. An A5 book with 60 interior pages on woodfree 90 kg and an art board 180 kg cover weighs about 111 g.

Spine Width Calculator & Book Cover Size | Spine Width from Page Count and Paper Thickness, Full Cover Size with Bleed (mm and px at 350/600 dpi), Cover Template PNG and SVG, Perfect Binding and Saddle Stitch Page Counts, Book Thickness and Weight, Zine Imposition (Saddle-Stitch Page Order)

The Spine Width Calculator answers “how wide is my spine?” and “what pixel size should my cover be?” when sending a self-published book, doujinshi or zine to a printer, and “in what order do I print the pages?” for a zine printed at home. Choose the trim size (A4, B5, A5, B6, A6 paperback, shinsho, shiroku or a custom size), perfect binding or saddle stitch, the number of interior pages and the interior paper (woodfree 55–110 kg, book paper, coated, matte coated, copy paper or a custom thickness). It calculates spine width = number of sheets × thickness of one sheet, and shows the trim size and the size with bleed of the full cover (front, spine and back in one piece) in mm and in px at 300, 350 and 600 dpi. You can save a cover template, drawn for right-to-left or left-to-right binding with the front and back covers, spine, bleed and safe area, as a PNG at the chosen dpi or as an SVG in mm. It also tells you how many blank pages to add when the page count is not a multiple of 4, whether the spine is wide enough for spine text, the thickness and weight of one book (basis weight converted from ream weight) and the weight of the whole print run. The zine imposition tab takes the total page count including covers and shows which pages go on the front and back of each sheet (saddle stitch, right-to-left or left-to-right) and the print order. A spine width chart, trim sizes with bleed in px, a paper thickness and basis weight table, and a glossary of terms such as cover 1–4, bleed and page numbers are included.

Calculate the spine width and cover size

Choose the trim size, binding, number of interior pages and interior paper to get the spine width and the size of the cover (front, spine and back) in mm and px.

Trim size

Binding

Binding direction

Interior pages (not counting the 4 cover pages)

pages

Interior paper (thickness per sheet is approximate)

Cover paper

Also add the cover thickness (×2) to the spine (to match your printer's method)

Bleed

Resolution

Copies (for total weight)

copies

Spine width

3.6mm

30 sheets × 0.12 mm

Cover size (with bleed)

305.6mm × 216mm

Trim 299.6mm × 210mm

Cover at 350 dpi

4211 × 2976px

One interior page (with bleed)

154mm × 216mm

2122 × 2976px (350dpi)

Interior sheets

30 sheets

Approx. book thickness

4mm

Approx. weight per book

111g

Interior 98g, cover 13g

Weight of 50 copies

5.54kg

You can put text on the spine, but keep it small rather than full width (it can shift 0.5–1 mm)
Paper thickness varies a little by brand and printer. Check your printer's spine chart or template before submitting.

Cover template (outside of the cover)

For right-to-left binding (vertical text, manga), seen from outside, the front cover is on the left and the back cover on the right.

ABOUT

About Spine Width Calculator & Book Cover Size | Spine Width from Page Count and Paper Thickness, Full Cover Size with Bleed (mm and px at 350/600 dpi), Cover Template PNG and SVG, Perfect Binding and Saddle Stitch Page Counts, Book Thickness and Weight, Zine Imposition (Saddle-Stitch Page Order)

The Spine Width Calculator works out the spine width of a self-published book or zine from its page count and paper thickness, and gives the full cover size with bleed in mm and px. It can also save a cover template as PNG or SVG, estimate the thickness and weight of a book, and lay out the pages of a home-printed saddle-stitched zine.

How to use Spine Width Calculator & Book Cover Size | Spine Width from Page Count and Paper Thickness, Full Cover Size with Bleed (mm and px at 350/600 dpi), Cover Template PNG and SVG, Perfect Binding and Saddle Stitch Page Counts, Book Thickness and Weight, Zine Imposition (Saddle-Stitch Page Order)

1In “Spine & cover size”, choose the trim size (A5, B5 etc.), the binding (perfect binding or saddle stitch) and the binding direction (right-to-left or left-to-right)
2Enter the number of interior pages (not counting the 4 cover pages) and choose the interior and cover paper. If your paper is not listed, choose “Enter thickness” and type your printer's value
3Check the spine width and the full cover size with bleed in mm and px
4Save the cover template as a PNG (350 dpi etc.) or SVG and place it under your artwork in your drawing app
5For a zine printed at home, enter the total page count including covers in “Zine imposition” and check which pages go on the front and back of each sheet and the print order

Great for

Calculating the spine width from the page count before sending a doujinshi or self-published book to the printer
Finding the canvas size in px, with bleed, for an A5 or B5 book cover
Checking whether the spine is wide enough to put the title on it
Estimating the weight of one book and of the whole run for an event or for shipping
Working out the page layout and print order for a zine printed on a home printer or at a convenience store
Looking up the approximate thickness and basis weight (gsm) of papers such as woodfree 70 kg and 90 kg

Good to know

The spine width is calculated as number of interior pages ÷ 2 (sheets) × thickness of one sheet. Some printers also add the cover thickness; if yours does, turn on “Also add the cover thickness”.
Paper thicknesses are approximate (woodfree 70 kg about 0.095 mm, 90 kg about 0.12 mm, etc.). The same ream weight can differ by brand and printer, so check your printer's spine chart or template before submitting.
The cover size is width = trim width × 2 + spine + bleed × 2, height = trim height + bleed × 2. Pixels are mm ÷ 25.4 × dpi, rounded.
The interior page count is normally a multiple of 4 (always for saddle stitch). If it is not, the tool shows how many blank pages to add.
The weight is an estimate from the basis weight (gsm), converted from the ream weight (kg per 1,000 shiroku-size sheets), multiplied by the paper area. Ink and glue are not included.
The zine imposition assumes saddle stitch: two pages side by side on landscape paper, duplex printing set to “flip on short edge”, then folded in half and stapled.

Questions this tool answers

Use Spine Width Calculator & Book Cover Size | Spine Width from Page Count and Paper Thickness, Full Cover Size with Bleed (mm and px at 350/600 dpi), Cover Template PNG and SVG, Perfect Binding and Saddle Stitch Page Counts, Book Thickness and Weight, Zine Imposition (Saddle-Stitch Page Order) for searches like these:

I want to calculate the spine width of my book
I want to know my book cover size in px
I want to make a book cover template
I want to know if my spine is wide enough for text
I want to know the page order (imposition) for a zine
I want to know how much one book weighs

FAQ

How do I calculate the spine width of a book?: Divide the number of interior pages by 2 to get the number of sheets, then multiply by the thickness of one sheet. For an A5 book with 60 interior pages on woodfree 90 kg paper (about 0.12 mm), that is 30 sheets × 0.12 mm = 3.6 mm. Some printers also add the cover thickness, so follow your printer's method.
What is the cover size of an A5 book in mm and px?: The cover is made as one piece: front, spine and back. For A5 (148 × 210 mm) with a 3.6 mm spine and 3 mm bleed, the width is 148 × 2 + 3.6 + 6 = 305.6 mm and the height is 210 + 6 = 216 mm, which is 4211 × 2976 px at 350 dpi. One interior page with bleed is 154 × 216 mm (2122 × 2976 px at 350 dpi).
What pixel size should B5 interior pages be?: B5 (182 × 257 mm) plus 3 mm bleed is 188 × 263 mm, which is 2591 × 3624 px at 350 dpi and 4441 × 6213 px at 600 dpi. Black-and-white comics are often made at 600 dpi and color pages at 350 dpi.
How wide must the spine be to print text on it?: It depends on the printer, but with a spine under 3 mm it is safest not to put text on it. Cutting and binding can shift by about 0.5–1 mm, so use small text for 3–5 mm and leave a little margin at both edges even at 5 mm or more.
In what order do I print the pages of a saddle-stitched zine?: For an 8-page right-to-left zine, sheet 1 has pages 1 and 8 on the front and 7 and 2 on the back, and sheet 2 has 3 and 6 on the front and 5 and 4 on the back (for left-to-right binding, left and right swap: 8 and 1, 2 and 7, 6 and 3, 4 and 5). Print on landscape paper with duplex set to “flip on short edge”, stack the sheets, fold them in half and staple along the fold. If the page count is not a multiple of 4, blank pages go before the back cover.
How thick and heavy is woodfree 70 kg or 90 kg paper?: As a guide, 70 kg is about 0.095 mm and 90 kg about 0.12 mm thick. The ream weight is the weight of 1,000 shiroku-size sheets (788 × 1091 mm); as basis weight (weight per m²), 70 kg is about 81 gsm and 90 kg about 105 gsm. An A5 book with 60 interior pages on woodfree 90 kg and an art board 180 kg cover weighs about 111 g.

Special Thanks

SOLO GUILD | サービス作るAIエンジニア

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