Calibre Ebook Conversion

ebook-convert (ships with Calibre) is the atomic command; don't wrap it in a script unless you need something genuinely more than one line. This skill is documentation + a couple of reusable command patterns.

Prerequisite

command -v ebook-convert || echo "Install Calibre and make sure ebook-convert is on PATH"

If ebook-convert isn't on PATH, resolve it per-platform (macOS app bundle, Linux package, Windows install dir) — don't hardcode a symlink path in the skill.

Core command

ebook-convert INPUT OUTPUT [options]

Format is inferred from the output extension.

ebook-convert novel.epub novel.mobi         # → Kindle
ebook-convert novel.epub novel.pdf          # → PDF
ebook-convert novel.mobi novel.epub         # → EPUB
ebook-convert novel.epub novel.azw3         # → AZW3

Batch convert

Bash one-liner — parallel, one output per input, same basename:

for f in *.epub; do ebook-convert "$f" "${f%.*}.mobi" & done; wait

Replace *.epub and .mobi with your source glob and target extension.

Kindle-tuned conversion

ebook-convert in.epub out.mobi \
  --output-profile kindle_pw3 \
  --mobi-file-type both \
  --no-inline-toc

Other useful flags:

• --cover path/to/cover.jpg — override cover image
• --authors "Name" / --title "..." — set metadata
• --margin-left/right/top/bottom 20 — for PDF output
• --pdf-page-numbers — for PDF output

Full reference: ebook-convert --help or ebook-convert in.epub out.mobi --help (format-specific options show up after the filenames).