install-ebook-convert.md

Install cask that extends the brew command :

brew install phinze/cask/brew-cask

Install calibre using cask :

brew cask install calibre

Setup $PATH for calibre (add ebook-convert and other commands to $PATH) :

export PATH="~/Applications/calibre.app/Contents/MacOS/:$PATH"

Or add it to your shell's .profile with :

echo 'export PATH=~/Applications/calibre.app/Contents/MacOS/:$PATH' >> ~/.profile

Now ebook-convert should be available :)

7 years later, we are down to a three word command! (--cask is optional)

brew install calibre

should be

echo 'export PATH=/Applications/calibre.app/Contents/MacOS/:$PATH' >> ~/.profile

brew install calibre
progress !!!

for M1 apple silicon

brew install calibre

ebook-convert /path/to/input /path/to/output

works