5.25 x 8 in · 90 pages

90-page 5.25 x 8 in book: spine width & cover size

A 90-page 5.25 x 8 in paperback has a spine of 0.2027 in (5.15 mm) on white paper or 0.225 in on cream. Full cover with bleed: 10.953 x 8.25 in.

0.203 inSpine, white paper5.15 mm

0.225 inSpine, cream paper5.72 mm

10.95 x 8.25Full cover, inchesincl. bleed

105 gEstimated weight3.7 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	0.2027 in	5.15 mm	10.953 x 8.25 in	278.2 x 209.6 mm	3,286 x 2,475 px
Cream paper, black ink	0.225 in	5.72 mm	10.975 x 8.25 in	278.8 x 209.6 mm	3,292 x 2,475 px
Standard color (white)	0.2027 in	5.15 mm	10.953 x 8.25 in	278.2 x 209.6 mm	3,286 x 2,475 px
Premium color (white)	0.2112 in	5.37 mm	10.961 x 8.25 in	278.4 x 209.6 mm	3,288 x 2,475 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)	0.2571 in	6.53 mm
400 PPI	Cream book paper (~55 lb)	0.225 in	5.72 mm
444 PPI	White book paper (~50 lb)	0.2027 in	5.15 mm
500 PPI	Lightweight text (~45 lb)	0.18 in	4.57 mm
600 PPI	Thin text (~40 lb)	0.15 in	3.81 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 10.953 x 8.25 in — or 3,286 x 2,475 px at 300 ppi.
The back cover runs from the left edge to 5.375 in; the spine from 5.375 to 5.578 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)
32 pages	0.0721 in	0.08 in	10.822 x 8.25 in
40 pages	0.0901 in	0.1 in	10.84 x 8.25 in
48 pages	0.1081 in	0.12 in	10.858 x 8.25 in
56 pages	0.1261 in	0.14 in	10.876 x 8.25 in
64 pages	0.1441 in	0.16 in	10.894 x 8.25 in
72 pages	0.1621 in	0.18 in	10.912 x 8.25 in
80 pages	0.1802 in	0.2 in	10.93 x 8.25 in
100 pages	0.2252 in	0.25 in	10.975 x 8.25 in
110 pages	0.2477 in	0.275 in	10.998 x 8.25 in
120 pages	0.2702 in	0.3 in	11.02 x 8.25 in
130 pages	0.2928 in	0.325 in	11.043 x 8.25 in
140 pages	0.3153 in	0.35 in	11.065 x 8.25 in
150 pages	0.3378 in	0.375 in	11.088 x 8.25 in

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

How wide is the spine of a 90-page 5.25 x 8 in book?

On white paper it is 0.2027 in (5.15 mm); on cream paper 0.225 in (5.72 mm), using KDP's per-page factors.

What size should the full cover be?

For white paper: 10.953 x 8.25 in (278.2 x 209.6 mm) including 0.125 in bleed on every side. For cream paper: 10.975 x 8.25 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 90-page 5.25 x 8 in paperback?

About 105 g (3.7 oz) on white paper with a standard cover — useful for estimating postage.