How KDP Spine Calculation Works
Amazon KDP uses specific paper thickness multipliers to calculate spine width. Getting this right ensures your cover fits perfectly without rejection.
White Paper
Best for non-fiction, textbooks
Pages × 0.002252"Cream Paper
Standard for fiction novels
Pages × 0.0025"Color Paper
Premium color printing
Pages × 0.002347"Using Both KDP and IngramSpark?
Note that IngramSpark uses slightly different spine width formulas than KDP due to variations in paper weight and manufacturing. Read our comparison guide to understand how to adjust your cover files for both platforms.