8.5 x 8.5 in Square · 80 pages

80-page 8.5 x 8.5 in book: spine width & cover size

A 80-page 8.5 x 8.5 in paperback has a spine of 0.1802 in (4.58 mm) on white paper or 0.2 in on cream. Full cover with bleed: 17.43 x 8.75 in.

0.18 inSpine, white paper4.58 mm

0.2 inSpine, cream paper5.08 mm

17.43 x 8.75Full cover, inchesincl. bleed

163 gEstimated weight5.8 oz

Cover template (white paper)

Red: bleed (trimmed off) · dashed: 0.25 in safe zone · shaded: spine. Download a full-size template from the calculator.

Paper	Spine	Spine (mm)	Full cover (in)	Full cover (mm)	At 300 ppi
White paper, black ink	0.1802 in	4.58 mm	17.43 x 8.75 in	442.7 x 222.3 mm	5,229 x 2,625 px
Cream paper, black ink	0.2 in	5.08 mm	17.45 x 8.75 in	443.2 x 222.3 mm	5,235 x 2,625 px
Standard color (white)	0.1802 in	4.58 mm	17.43 x 8.75 in	442.7 x 222.3 mm	5,229 x 2,625 px
Premium color (white)	0.1878 in	4.77 mm	17.438 x 8.75 in	442.9 x 222.3 mm	5,231 x 2,625 px

Per-page factors are those published by KDP; IngramSpark and offset printers use their own paper calipers.

Paper PPI	Typical stock	Spine	Spine (mm)
350 PPI	Bulky / heavy stock (~70 lb text)	0.2286 in	5.81 mm
400 PPI	Cream book paper (~55 lb)	0.2 in	5.08 mm
444 PPI	White book paper (~50 lb)	0.1802 in	4.58 mm
500 PPI	Lightweight text (~45 lb)	0.16 in	4.06 mm
600 PPI	Thin text (~40 lb)	0.1333 in	3.39 mm

If your printer quotes pages per inch (PPI), spine = pages ÷ PPI. Ask for the exact PPI of your chosen stock.

Build the cover canvas at 17.43 x 8.75 in — or 5,229 x 2,625 px at 300 ppi.
The back cover runs from the left edge to 8.625 in; the spine from 8.625 to 8.805 in; the front cover after that.
Spine text is allowed — centre it and keep 0.0625 in clear on each side.
Keep titles and faces at least 0.25 in inside the trim; KDP places the barcode in a 2 x 1.2 in area at the lower right of the back cover.
Export as a flattened PDF (PDF/X-1a is safest) with fonts embedded.

Pages	Spine (white)	Spine (cream)	Full cover (white)
24 pages	0.054 in	0.06 in	17.304 x 8.75 in
32 pages	0.0721 in	0.08 in	17.322 x 8.75 in
40 pages	0.0901 in	0.1 in	17.34 x 8.75 in
48 pages	0.1081 in	0.12 in	17.358 x 8.75 in
56 pages	0.1261 in	0.14 in	17.376 x 8.75 in
64 pages	0.1441 in	0.16 in	17.394 x 8.75 in
72 pages	0.1621 in	0.18 in	17.412 x 8.75 in
90 pages	0.2027 in	0.225 in	17.453 x 8.75 in
100 pages	0.2252 in	0.25 in	17.475 x 8.75 in
110 pages	0.2477 in	0.275 in	17.498 x 8.75 in
120 pages	0.2702 in	0.3 in	17.52 x 8.75 in
130 pages	0.2928 in	0.325 in	17.543 x 8.75 in
140 pages	0.3153 in	0.35 in	17.565 x 8.75 in

Spine width depends only on page count and paper; the cover width changes with the trim.

How wide is the spine of a 80-page 8.5 x 8.5 in book?

On white paper it is 0.1802 in (4.58 mm); on cream paper 0.2 in (5.08 mm), using KDP's per-page factors.

What size should the full cover be?

For white paper: 17.43 x 8.75 in (442.7 x 222.3 mm) including 0.125 in bleed on every side. For cream paper: 17.45 x 8.75 in.

Can I put text on the spine?

Yes. KDP allows spine text only for books with more than 79 pages; keep it at least 0.0625 in (1.6 mm) from each spine edge.

How heavy is a 80-page 8.5 x 8.5 in paperback?

About 163 g (5.8 oz) on white paper with a standard cover — useful for estimating postage.