Book Cover Dimensions for US Authors

The US market is dominated by Amazon KDP, which accepts over 30 trim sizes for paperback covers. The three most popular sizes for US trade paperbacks are 5.5" x 8.5", 6" x 9", and 5" x 8". Your cover dimensions depend on the trim size you choose, your page count, and whether you use white or cream paper — cream paper is thicker (0.0025" per page vs 0.002252" for white), producing a wider spine.

KDP requires all paperback covers to include 0.125" (3.175 mm) bleed on all four sides. This means your submitted cover file must be larger than the final trim size. For a 6" x 9" book with 250 pages on cream paper, the spine width is 0.625", making the full cover file 12.375" x 9.25" (including bleed). At 300 DPI, that's 3713 x 2775 pixels.

The safe zone — the area where text and important graphics should stay — is 0.25" from the trim edge on all sides and 0.0625" from each edge of the spine. Anything outside this area risks being cut off during printing. The barcode area on the back cover should be positioned in the lower-right quadrant, at least 0.25" from all edges.

For US authors using IngramSpark alongside KDP, note that IngramSpark uses slightly different paper thickness values: 0.002347" per page for white and 0.002602" per page for cream. This means your IngramSpark spine will be marginally wider than KDP for the same page count. If you're publishing on both platforms, design your cover using the larger spine measurement and verify it meets both platforms' requirements.

Hardcover (case laminate) covers on KDP have additional requirements. The cover wraps around a rigid board, adding approximately 0.25" to the spine width calculation. Hardcovers also require a larger bleed area of 0.625" on all four sides. The calculator above handles these differences automatically when you select the hardcover option.