Book Cover Dimensions for UK Authors

UK authors typically favour the B-format size (5.06" x 7.81" / 129 x 198 mm) for fiction paperbacks, which is the standard size on UK bookshop shelves. However, KDP trim sizes are specified in inches and don't include an exact B-format match. The closest KDP sizes are 5" x 8" and 5.25" x 8". For non-fiction trade paperbacks, 6" x 9" is the most popular choice in the UK market, consistent with US conventions.

Amazon.co.uk printing uses the same paper thickness values as Amazon.com — 0.002252" per page for white paper and 0.0025" per page for cream. Your spine width calculation is identical regardless of which Amazon marketplace you sell through. A 300-page novel on cream paper has a spine width of 0.75" (19.05 mm) on both Amazon.co.uk and Amazon.com.

For UK authors selling through IngramSpark, which connects to Gardners (the UK's largest book wholesaler), cover dimensions follow IngramSpark's paper thickness: 0.002347" per page for white and 0.002602" per page for cream. Gardners and UK bookshops expect ISBN barcodes on the back cover — use our ISBN Barcode Generator tool to create a print-ready barcode after calculating your cover dimensions.

UK printing through KDP produces books at Amazon's UK print facility, which means faster delivery to UK customers (3-5 business days vs 2-3 weeks for US-printed books shipped internationally). The cover quality is identical to US printing — matte or glossy laminate finish at 300 DPI. Always upload at the full required resolution; KDP will not upscale low-resolution files.

If you're distributing through both KDP and IngramSpark UK, design your cover file using the larger of the two spine width calculations. A slightly wider spine on the narrower platform will be trimmed imperceptibly, but a spine that's too narrow will show white edges — a visible production flaw that undermines your book's professional appearance.