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KDP cover calculator

Exact spine width and full cover size, with a print-ready template to design on.

Printer
Spine width
Units
0.750 in
Full cover with bleed
13.000 in x 9.250 in
At 300 PPI
3900 x 2775 px
Spine text area
0.625 in wide
    13.000 in9.250 inBack coverFront coverSpine
    Bleed, trimmed offTrimSpine foldsKeep text insideBarcode

    Rather have a pro handle this? Our studio can: book cover design.

    How to use it

    1. Pick your printer: KDP, IngramSpark or Lulu.
    2. Choose your trim size, or enter a custom one.
    3. Enter your final page count, and for KDP the paper and ink you will select at upload.
    4. For IngramSpark, paste the spine width from IngramSpark's spine calculator.
    5. Download the PNG or PDF template and design your cover on top of it.

    How it works

    A paperback cover is one flat sheet: back cover, spine and front cover side by side, plus bleed on every outside edge. The spine is the only part that changes with your page count.

    Spine width = page count x paper thickness
    Cover width = bleed + trim width + spine + trim width + bleed
    Cover height = bleed + trim height + bleed

    Worked example: a 6 x 9 in KDP paperback with 300 cream pages. The spine is 300 x 0.0025 in = 0.750 in. The cover width is 0.125 in + 6 in + 0.750 in + 6 in + 0.125 in = 13.000 in, and the height is 0.125 in + 9 in + 0.125 in = 9.250 in.

    Lulu adds a fixed amount to its rate: spine = pages / 444 + 0.060 in. IngramSpark gives its widths through its own calculator, so you paste that number in.

    Reference

    Spine width in inches by page count. KDP standard color matches KDP white.

    Printer and paper100 pp200 pp300 pp400 pp500 pp600 pp
    KDP, white paper, black ink0.2250.4500.6760.9011.1261.351
    KDP, cream paper, black ink0.2500.5000.7501.0001.2501.500
    KDP, groundwood paper, black ink0.2350.4700.7050.9401.1751.410
    KDP, premium color0.2350.4690.7040.9391.1731.408
    Lulu, any paper0.2850.5100.7360.9611.1861.411

    Questions authors ask

    How do I calculate the spine width for a KDP paperback?

    Multiply your page count by KDP's rate for your paper: 0.002252 in per page for white, 0.0025 in for cream, 0.00235 in for groundwood, 0.002252 in for standard color and 0.002347 in for premium color. A 300 page book on cream paper has a 0.750 in spine.

    How big is the full cover file for a KDP paperback?

    Width is bleed + back cover + spine + front cover + bleed. Height is bleed + trim height + bleed. KDP bleed is 0.125 in, so a 6 x 9 in book with a 0.750 in spine needs a 13.000 in x 9.250 in cover.

    How many pages do I need for text on the spine?

    KDP's help pages give 79 pages in one place and "more than 79" in another, and its Cover Creator needs 80, so we warn below 80. IngramSpark allows spine text from 48 pages. Lulu asks for no spine text at 80 pages or fewer. Below those counts, keep the spine plain.

    Why does cream paper make a thicker spine?

    Cream paper is thicker than white. At KDP it adds 0.0025 in per page against 0.002252 in for white, so switching paper after your cover is done changes the spine and the full cover width.

    Can I use the same cover file for KDP and IngramSpark?

    Usually not. Each printer uses its own paper, so the same page count gives a different spine width and full cover width. Barcode and safety rules differ too. Make one file per printer from the same artwork.

    Why do I have to paste the spine width for IngramSpark?

    IngramSpark doesn't publish a spine formula. Its spine calculator returns a width for each page count and paper, and those widths don't follow a simple rate. To stay exact, take the number from their calculator and paste it here. We still handle bleed, safety areas, barcode space and the template.

    What do I do with the template?

    Put the PNG or PDF on the top layer in your design app, design underneath it, then hide the template before you export. The PNG is 300 PPI and opens at full print size. Extend background art to the outer edge, keep text inside the dashed boxes, and keep the spine centered between the fold lines.

    Is my book information sent anywhere?

    No. The calculator and both downloads run in your browser. Nothing you type leaves your device, and there is no signup.

    Before and after this step

    Read the guide

    Related tools

    Sources

    Last verified against each printer's official help pages. Printers change their specs, so check the source before you order a proof.

    KDP

    IngramSpark

    Lulu