Amazon KDP (Kindle Direct Publishing) is strict about image quality. Getting rejected because of DPI, the wrong color space, or incorrect dimensions is frustrating — especially when you're moments away from publishing. This is the complete checklist.
1. Book Cover Requirements
Your book cover is the most important image in your KDP submission. KDP is particularly strict here.
| Requirement | Spec |
|---|---|
| Minimum DPI | 300 DPI |
| File format | JPEG (.jpg) only |
| Color space | RGB (not CMYK) |
| Aspect ratio | Between 1:1.6 and 1:2.5 (height:width) |
| Minimum size | 625 × 1000 pixels |
| Ideal size | 2560 × 1600 pixels (for eBook) |
| Maximum file size | 50 MB |
| No bleed required | Cover tool handles bleed separately |
Calculating Print Cover Dimensions
For a print book (paperback), the cover dimensions depend on your trim size and page count. KDP provides a cover template generator. The general formula:
- Width: (front width + spine width + back width) × 300 DPI
- Spine width: Approximately 0.002252 inches × page count (for white paper)
For example, a 6×9 book with 200 pages: spine ≈ 0.45 inch. Total width = 6 + 0.45 + 6 = 12.45 inches × 300 DPI = 3735px wide. Height = 9 + 0.25 bleed × 2 = 9.5 inches × 300 = 2850px tall.
2. Interior Image Requirements
Images embedded inside your manuscript (photos, illustrations, diagrams) have their own requirements.
| Requirement | Black & White Interior | Color Interior |
|---|---|---|
| Minimum DPI | 300 DPI | 300 DPI |
| Format | JPEG or PNG | JPEG or PNG |
| Color space | Grayscale or RGB | RGB |
| Compression | Not excessive | Not excessive |
3. eBook (Kindle) Image Requirements
eBook images are different — Kindle devices and apps display at screen resolution, so pixel dimensions matter more than DPI.
| Requirement | Spec |
|---|---|
| Format | JPEG or PNG |
| Recommended width | 2560px (for HD displays) |
| Minimum width | 600px |
| Color space | RGB |
| Cover aspect ratio | 1:1.6 recommended |
4. Common KDP Rejection Reasons
Here are the most common errors and how to fix them:
Error: "Image resolution is too low"
This means your DPI metadata tag is below 300. Fix: Use our KDP Image Tool to update it to 300 DPI. Takes 10 seconds.
If the error persists after updating DPI, your image may genuinely lack enough pixels. Calculate: width in inches × 300 = minimum pixel width needed.
Error: "Image is CMYK, must be RGB"
KDP requires RGB color space. CMYK is used for offset printing. Open your image in Photoshop → Image → Mode → RGB Color. Or use any online converter to convert CMYK to RGB.
Error: "Cover dimensions don't meet requirements"
Download KDP's official cover template (available in KDP dashboard) for your exact trim size and page count. Design to those precise pixel dimensions.
Error: "File format not supported"
Covers must be JPEG. PNG is not accepted for covers. Interior images can be JPEG or PNG.
5. Pre-Submission Checklist
Before submitting to KDP, verify:
- ✓ DPI is 300 or higher (use our DPI Checker)
- ✓ Color space is RGB (not CMYK)
- ✓ Format is JPEG for cover, JPEG/PNG for interior
- ✓ Pixel dimensions are sufficient for print size at 300 DPI
- ✓ No white or black borders added by image editor (unless intentional)
- ✓ Text is legible at thumbnail size (for cover)
- ✓ Bleed area is included if required by your cover template
6. Tools We Recommend
| Task | Free Tool |
|---|---|
| Fix DPI metadata | ConvertImageDPI KDP Tool |
| Check current DPI | ConvertImageDPI Checker |
| Design book cover | Canva, Affinity Publisher (free trial) |
| Convert CMYK to RGB | Photopea (free, online) |
| KDP cover template | KDP dashboard → Paperback → Launch Cover Creator |