Leaf & Spine

5.25 x 8 in · 380 pages

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

A 380-page 5.25 x 8 in paperback has a spine of 0.8558 in (21.74 mm) on white paper or 0.95 in on cream. Full cover with bleed: 11.606 x 8.25 in.

0.856 inSpine, white paper21.74 mm
0.95 inSpine, cream paper24.13 mm
11.61 x 8.25Full cover, inchesincl. bleed
401 gEstimated weight14.1 oz

Cover template (white paper)

Barcode areaBACK COVER5.25 x 8 inFRONT COVER5.25 x 8 inSPINE 0.856 inFull cover 11.606 x 8.25 in incl. 0.125 in bleed
Red: bleed (trimmed off) · dashed: 0.25 in safe zone · shaded: spine. Download a full-size template from the calculator.

Spine and cover by paper type

PaperSpineSpine (mm)Full cover (in)Full cover (mm)At 300 ppi
White paper, black ink0.8558 in21.74 mm11.606 x 8.25 in294.8 x 209.6 mm3,482 x 2,475 px
Cream paper, black ink0.95 in24.13 mm11.7 x 8.25 in297.2 x 209.6 mm3,510 x 2,475 px
Standard color (white)0.8558 in21.74 mm11.606 x 8.25 in294.8 x 209.6 mm3,482 x 2,475 px
Premium color (white)0.8919 in22.65 mm11.642 x 8.25 in295.7 x 209.6 mm3,493 x 2,475 px

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

Other printers: spine by paper PPI

Paper PPITypical stockSpineSpine (mm)
350 PPIBulky / heavy stock (~70 lb text)1.0857 in27.58 mm
400 PPICream book paper (~55 lb)0.95 in24.13 mm
444 PPIWhite book paper (~50 lb)0.8559 in21.74 mm
500 PPILightweight text (~45 lb)0.76 in19.3 mm
600 PPIThin text (~40 lb)0.6333 in16.09 mm

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

Designing this cover

  • Build the cover canvas at 11.606 x 8.25 in — or 3,482 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 6.231 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.

Nearby page counts

PagesSpine (white)Spine (cream)Full cover (white)
320 pages0.7206 in0.8 in11.471 x 8.25 in
330 pages0.7432 in0.825 in11.493 x 8.25 in
340 pages0.7657 in0.85 in11.516 x 8.25 in
350 pages0.7882 in0.875 in11.538 x 8.25 in
360 pages0.8107 in0.9 in11.561 x 8.25 in
370 pages0.8332 in0.925 in11.583 x 8.25 in
390 pages0.8783 in0.975 in11.628 x 8.25 in
400 pages0.9008 in1 in11.651 x 8.25 in
410 pages0.9233 in1.025 in11.673 x 8.25 in
420 pages0.9458 in1.05 in11.696 x 8.25 in
430 pages0.9684 in1.075 in11.718 x 8.25 in
440 pages0.9909 in1.1 in11.741 x 8.25 in

380 pages in other trim sizes

TrimSpine (white)Full cover (white)
5 x 8 in0.8558 in11.106 x 8.25 in
5.06 x 7.81 in0.8558 in11.226 x 8.06 in
5.5 x 8.5 in0.8558 in12.106 x 8.75 in
6 x 9 in0.8558 in13.106 x 9.25 in
6.14 x 9.21 in0.8558 in13.386 x 9.46 in
6.69 x 9.61 in0.8558 in14.486 x 9.86 in
7 x 10 in0.8558 in15.106 x 10.25 in
7.5 x 9.25 in0.8558 in16.106 x 9.5 in
8 x 10 in0.8558 in17.106 x 10.25 in
8.5 x 8.5 in0.8558 in18.106 x 8.75 in
8.5 x 11 in0.8558 in18.106 x 11.25 in

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

Frequently asked questions

How wide is the spine of a 380-page 5.25 x 8 in book?
On white paper it is 0.8558 in (21.74 mm); on cream paper 0.95 in (24.13 mm), using KDP's per-page factors.
What size should the full cover be?
For white paper: 11.606 x 8.25 in (294.8 x 209.6 mm) including 0.125 in bleed on every side. For cream paper: 11.7 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 380-page 5.25 x 8 in paperback?
About 401 g (14.1 oz) on white paper with a standard cover — useful for estimating postage.