Free tool for KDP authors
KDP Book Cover Size Calculator
Enter your book details to get the exact dimensions for your Amazon KDP print cover, including total cover size, spine width, bleed, margins, and safe areas, updated instantly as you type.
| Diagram key | Measurement | Width | Height |
|---|---|---|---|
| 1 | Total Cover | Width10.926" | Height8.25" |
| 2 | Front/back cover panel size | Width5" | Height8" |
| 3 | Bleed (per side) | Width0.125" | Height0.125" |
| 4 | Margin (per side) | Width0.125" | Height0.125" |
| 5 | Spine | Width0.676" | Height8" |
| 6 | Spine Margin (per side) | Width0.062" | Height0.062" |
| 7 | Barcode Margin | Width0.25" | Height0.25" |
Coverjig calculates your cover measurements as you design, so you don’t need to set them up yourself.
Cover Measurements explained
Understanding Your paperback Dimensions
Get familiar with the print terms behind your cover measurements.
Bleed Area
Bleed is the extra 0.125" of design that extends beyond the trim line on each side. It ensures no white edges appear if the cover is cut slightly off-centre during printing.
Margin
Leave a 0.125" margin at the top, bottom, and outside edge of each cover panel. Keep important content inside the safe area and out of the spine.
Spine Width
Spine width is determined by your page count and paper type. A higher page count means a wider spine. KDP requires at least 79 pages for paperbacks before spine text is allowed.
Want to learn more?
Read our full guide to bleed areas and marginsUsing your measurements
How Your KDP Cover Size Is Calculated
A quick guide to the measurements behind your print-ready cover.
What this calculator measures
A KDP cover file needs room for the back cover, spine, front cover, and the extra area that extends beyond the trim line. This calculator brings those measurements together in one place. If you use Coverjig, the same measurements are applied to your cover automatically. The margin, safe area, and barcode margin also show where important text and artwork should go.
What changes the cover size?
The cover size depends on more than the trim size. Page count and paper type affect the spine width, while the book format changes the allowances around the panels. Select the format, trim size, page count, and paper type that match your book, and the calculator will update the measurements for you.
Paperback and hardcover covers
Paperback covers use a front panel, back panel, spine, and bleed. Hardcover covers also include the wrap and hinge areas needed for the case boards. Coverjig includes these areas automatically when it prepares your cover. When working in another design program, extend background artwork through the outer areas and keep titles, author names, and other important details inside the safe area.
How to use the results
You do not need to set up cover dimensions or guides yourself when designing in Coverjig. The design tool uses your book details to apply the correct cover size and placement areas automatically. If you are using another program, use the total width and height to create your document and refer to the diagram when placing artwork and text.
Supported KDP Paperback trim sizes
- 5 x 8 inches
- 5.06 x 7.81 inches
- 5.25 x 8 inches
- 5.5 x 8.5 inches
- 6 x 9 inches
- 6.14 x 9.21 inches
- 6.69 x 9.61 inches
- 7 x 10 inches
- 7.44 x 9.69 inches
- 7.5 x 9.25 inches
- 8 x 10 inches
- 8.25 x 6 inches
- 8.25 x 8.25 inches
- 8.27 x 11.69 inches
- 8.5 x 8.5 inches
- 8.5 x 11 inches
Supported KDP Hardcover trim sizes
- 5.5 x 8.5 inches
- 6 x 9 inches
- 6.14 x 9.21 inches
- 7 x 10 inches
- 8.25 x 11 inches
Questions authors ask
About this calculator.
Q01How accurate are these dimensions?
This calculator uses Amazon KDP's official trim size, bleed and paper thickness specifications, the same figures Coverjig's design tool uses to format your cover.
Q02What's the difference between bleed, margin, and safe area?
The bleed area extends beyond the trim line so that no white edges appear if trimming shifts slightly during printing. The margin is the area near the outside edges where text should not be placed. The safe area is the region inside the dotted guide where important content can go.
Q03Why is my spine width so small?
Spine width is calculated mostly by the page count and paper type. Short books have thin spines, and KDP requires a minimum page count (79 for paperback, 75 for hardcover) before it will allow text on the spine.
Q04Do hardcovers use different margins to paperbacks?
Yes. Hardcovers add a board thickness allowance and a wider bleed and hinge area to account for the case binding, which this calculator applies automatically when you switch format.
Q05Can I use these numbers directly in my design software?
Yes. The total cover width and height give you the exact page size to set up, with the spine width and margins as reference guides.
Q06Can I skip this and just design my cover?
Yes. Coverjig calculates and applies all of these measurements automatically once you enter your book details in the design tool, so this calculator is entirely optional.
Start your book cover
Ready to Design Your KDP Cover?
Coverjig calculates the correct measurements automatically, so you can focus on the design of your cover.