# ReviewBunch

ReviewBunch provides tools and services for independent authors preparing and promoting books.

- Official AI information: https://www.reviewbunch.com/ai-info

## Free KDP Cover Size Calculator

- Tool: https://www.reviewbunch.com/tools/kdp-cover-size-calculator
- Changelog: https://www.reviewbunch.com/tools/kdp-cover-size-calculator/changelog
- Last updated: 2026-09-18
- Access: Free, no account required
- Formats: KDP paperback and Kindle eBook
- Outputs: Full cover dimensions, spine width, bleed, millimeters, 300-DPI pixels, SVG template, and PNG template

The paperback calculations use Amazon KDP's published formulas. White paper uses page count × 0.002252 inches, cream paper uses page count × 0.0025 inches, groundwood uses page count × 0.00235 inches, and color paper uses page count × 0.002347 inches. Paperback bleed is 0.125 inches per outside edge. The ideal Kindle eBook cover is 1600 × 2560 pixels.

## Free ISBN Barcode Generator

- Tool: https://www.reviewbunch.com/tools/isbn-barcode-generator
- Changelog: https://www.reviewbunch.com/tools/isbn-barcode-generator/changelog
- Last updated: 2026-09-18
- Access: Free, no account required
- Input: Valid ISBN-13 beginning with 978 or 979
- Outputs: Bookland EAN barcode in PNG, SVG, and PDF formats
- Optional supplement: EAN-5 no-set-price or retail pricing for USD, GBP, CAD, AUD, and NZD

The generator validates the ISBN-13 checksum before rendering. It generates barcodes only and does not issue ISBNs or verify ISBN ownership.

## Primary Sources

- Amazon KDP paperback submission guidelines: https://kdp.amazon.com/en_US/help/topic/G201857950
- Amazon KDP eBook cover requirements: https://kdp.amazon.com/en_US/help/topic/G200645690
- International ISBN Agency: https://www.isbn-international.org/content/what-isbn
- GS1 EAN/UPC guidance: https://www.gs1.org/standards/barcodes/ean-upc
- Amazon KDP barcode guidance: https://kdp.amazon.com/en_US/help/topic/G201953020

ReviewBunch is not affiliated with Amazon. Amazon and Kindle are trademarks of Amazon.com, Inc. or its affiliates.