5.5 x 8.5 in Digest · 420 pages

420-page 5.5 x 8.5 in book: spine width & cover size

A 420-page 5.5 x 8.5 in paperback has a spine of 0.9458 in (24.02 mm) on white paper or 1.05 in on cream. Full cover with bleed: 12.196 x 8.75 in.

0.946 inSpine, white paper24.02 mm

1.05 inSpine, cream paper26.67 mm

12.2 x 8.75Full cover, inchesincl. bleed

491 gEstimated weight17.3 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	0.9458 in	24.02 mm	12.196 x 8.75 in	309.8 x 222.3 mm	3,659 x 2,625 px
Cream paper, black ink	1.05 in	26.67 mm	12.3 x 8.75 in	312.4 x 222.3 mm	3,690 x 2,625 px
Standard color (white)	0.9458 in	24.02 mm	12.196 x 8.75 in	309.8 x 222.3 mm	3,659 x 2,625 px
Premium color (white)	0.9857 in	25.04 mm	12.236 x 8.75 in	310.8 x 222.3 mm	3,671 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)	1.2 in	30.48 mm
400 PPI	Cream book paper (~55 lb)	1.05 in	26.67 mm
444 PPI	White book paper (~50 lb)	0.9459 in	24.03 mm
500 PPI	Lightweight text (~45 lb)	0.84 in	21.34 mm
600 PPI	Thin text (~40 lb)	0.7 in	17.78 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 12.196 x 8.75 in — or 3,659 x 2,625 px at 300 ppi.
The back cover runs from the left edge to 5.625 in; the spine from 5.625 to 6.571 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)
360 pages	0.8107 in	0.9 in	12.061 x 8.75 in
370 pages	0.8332 in	0.925 in	12.083 x 8.75 in
380 pages	0.8558 in	0.95 in	12.106 x 8.75 in
390 pages	0.8783 in	0.975 in	12.128 x 8.75 in
400 pages	0.9008 in	1 in	12.151 x 8.75 in
410 pages	0.9233 in	1.025 in	12.173 x 8.75 in
430 pages	0.9684 in	1.075 in	12.218 x 8.75 in
440 pages	0.9909 in	1.1 in	12.241 x 8.75 in
450 pages	1.0134 in	1.125 in	12.263 x 8.75 in
460 pages	1.0359 in	1.15 in	12.286 x 8.75 in
470 pages	1.0584 in	1.175 in	12.308 x 8.75 in
480 pages	1.081 in	1.2 in	12.331 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 420-page 5.5 x 8.5 in book?

On white paper it is 0.9458 in (24.02 mm); on cream paper 1.05 in (26.67 mm), using KDP's per-page factors.

What size should the full cover be?

For white paper: 12.196 x 8.75 in (309.8 x 222.3 mm) including 0.125 in bleed on every side. For cream paper: 12.3 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 420-page 5.5 x 8.5 in paperback?

About 491 g (17.3 oz) on white paper with a standard cover — useful for estimating postage.