Self-Hosted Calendar (CalDAV)
To replace Google Calendar you want a CalDAV server your phone and computer sync to. Three options cover it: Baikal for a simple standalone server, Radicale for the lightest possible setup, and Nextcloud Calendar if you want calendar alongside files and contacts.
Updated 2026-06-03 · by Jonathan Caruso
Top pick
Baikal
Baikal is a lightweight CalDAV and CardDAV server with a simple web admin. It handles calendars and contacts, syncs cleanly with phones and desktops, and runs on almost nothing, which makes it the easiest standalone Google Calendar replacement.
The options
Baikal
GPL, freeA lightweight CalDAV/CardDAV server with a simple admin UI.
Visit Baikal site- Runs on
- PHP, tiny. Runs on a Raspberry Pi.
- Pick it if
- You want a simple standalone calendar and contacts server.
Radicale
GPL, freeAn extremely lightweight CalDAV/CardDAV server with minimal config.
Visit Radicale site- Runs on
- Python, tiny.
- Pick it if
- You want the smallest, simplest possible sync server.
Nextcloud Calendar
AGPL, freeA full calendar app inside Nextcloud, sharing one server with files and contacts.
Visit Nextcloud Calendar site- Runs on
- Runs on an existing Nextcloud instance.
- Pick it if
- You already run Nextcloud and want calendar in the same place.
How to choose
If you just want calendars and contacts that sync to your devices, Baikal or Radicale is the answer, and the choice is mostly taste: Baikal has a friendlier admin UI, Radicale is even leaner and configured with text files. Both speak standard CalDAV, so any phone or desktop calendar app can connect.
If you want calendar as part of a broader self-hosted suite, run Nextcloud and use its calendar app so your files, contacts, and calendar share one login. That is more to host than a standalone CalDAV server, but it replaces more of Google at once.
The verdict
For a standalone Google Calendar replacement, run Baikal: it is light, handles calendars and contacts, and syncs cleanly with every device over CalDAV. Choose Radicale for the absolute lightest setup, or Nextcloud Calendar if you want calendar bundled with files and contacts. See our self-hosted alternative to Dropbox if Nextcloud appeals.
FAQ
How do I replace Google Calendar with a self-hosted one?
Run a CalDAV server (Baikal, Radicale, or Nextcloud), then add the account to your phone and computer's calendar app using its CalDAV URL. Your existing calendar apps keep working; only the server changes.
Will it sync with my iPhone and Android?
Yes. CalDAV is a standard, so iOS Calendar, Android (via a CalDAV client like DAVx5), Thunderbird, and others all sync to Baikal, Radicale, or Nextcloud.
Which is the lightest?
Radicale, which runs on almost nothing and is configured with simple text files. Baikal is also very light and adds a friendlier admin UI.