Backing up contacts prior to OS reinstall

[danimations]

Is it possible/practical to backup my contacts somehow, then restore them after I've reinstalled the operating system?

If so, a step-by-step guide to achieving this would be greatly appreciated.

[acrux]

You did not specify the shell - Plasma Mobile or Phosh?
In Plasma Mobile I'm using a combo usbA&usbC memory stick and copy there the following files:
/.config/KDE/plasma-phonebook.conf
and directories:
/.local/share/kpeople
/.local/share/kpeoplevcard
Just with Index file manager

[Uturn]

i keep them on my nextcloud, but with KDE plasma mobile, only contacts. For calendar items I must learn vdirsyncer.
With vdirsyncer, you should be able to save your contacts to a local directory too, by the way.
And then sync them back to your new install.

[kqlnut]

On Phosh the contacts are stored in .local/share/evolution/addressbook. You can just backup and restore that folder.