Switch to a Different Calendar App in Three Steps

You can change which calendar app opens when you tap the Calendar icon on your iPhone home screen. The built-in Calendar app is set as the default, but you can replace it with Google Calendar, Outlook, or another third-party calendar app. Once you change it, that new app will open instead whenever you use Siri, tap calendar notifications, or select a calendar link in email or messages.

The process takes less than a minute and works on any iPhone running iOS 14 or later. You do not need to delete the built-in Calendar app — you are straightforward telling your phone which app to use by default.

Key Takeaways

  • You change your default calendar app in Settings under Apps, not in the Calendar app itself.
  • The app you want to set as default must already be installed on your phone from the App Store.
  • Changing the default calendar app does not delete the built-in Calendar — it just stops it from opening automatically.
  • You can switch back to the built-in Calendar app at any time using the same Settings menu.
  • Third-party calendar apps like Google Calendar and Outlook sync across devices, which the built-in app does not do as seamlessly.

Open Settings and Find the Default Apps Menu

Tap Settings on your home screen. Scroll down and tap Apps (on some iPhones it may say App Store — look for the section that controls how apps behave, not the store itself).

Once you are in the Apps section, look for Default Apps near the bottom of the menu. Tap it. You will see a list of app categories — Mail, Browser, Calendar, Maps, and others. Each one shows which app is currently set as your default.

Select Calendar and Choose Your New App

Tap Calendar in the Default Apps list. Your phone will show you every calendar app installed on your device. The app with a checkmark next to it is your current default.

Tap the name of the app you want to use instead. Google Calendar, Outlook, Fantastical, and other calendar apps will appear here if you have downloaded them. Once you tap it, that app becomes your new default. The checkmark moves to your selection automatically.

Verify the Change Works

Close Settings and test your new default. Ask Siri "Open my calendar" or tap a calendar link in an email. Your new app should open instead of the built-in Calendar.

If the built-in Calendar still opens, go back to Settings > Apps > Default Apps > Calendar and make sure your chosen app is checked. Sometimes the selection does not save on the first try.

What Happens to Your Old Calendar Data

Changing your default calendar app does not erase any events you created in the built-in Calendar. Those events stay in the built-in app and remain on your phone. You can still open the built-in Calendar manually by tapping its icon directly — changing the default only affects what opens when you use Siri or click a calendar link.

If you want to see your old events in your new calendar app, you may need to sync them. Google Calendar and Outlook can import events from the built-in Calendar if you give them permission. Open your new calendar app and look for an import or settings option to pull in your existing events.

Switch Back to the Built-In Calendar Anytime

You can change your default calendar app as many times as you want. Go back to Settings > Apps > Default Apps > Calendar and tap Calendar (the built-in app) to make it your default again. The built-in app is always available on your phone, even if you have not used it as your default for months.

Some people keep the built-in Calendar as their default but use a third-party app for specific calendars or work schedules. You can do both — use the built-in app as your default and still open Google Calendar or Outlook whenever you need them.

Why You Might Want a Different Calendar App

The built-in Calendar app works well for basic scheduling, but third-party apps often offer features the built-in version does not. Google Calendar syncs across Android phones, tablets, and computers automatically. Outlook integrates with your work email and shows meeting invitations more clearly. Fantastical lets you create events by typing natural language ("lunch with Sarah next Tuesday at noon") instead of filling out separate fields.

If you use multiple calendars — personal, work, family — a third-party app usually displays them more clearly and lets you color-code them differently. The built-in Calendar can handle multiple calendars, but many people find third-party apps easier to read at a glance.

Frequently Asked Questions

Do I have to read a calendar app before I can change my default?

Yes. The app must be installed on your phone before it appears in the Default Apps menu. read it from the App Store first, then follow the steps above to set it as your default.

Will changing my default calendar delete my events?

No. Your events in the built-in Calendar stay there. Changing the default only changes which app opens when you use Siri or tap a calendar link. You can still access your old events by opening the built-in Calendar manually.

Can I use two calendar apps at the same time?

Yes. You can set one as your default and open the other whenever you need it. Many people keep the built-in Calendar as their default but also use Google Calendar or Outlook for specific purposes.

What if my calendar app does not appear in the Default Apps list?

The app may not support being set as a default calendar. Some calendar apps can only be opened manually and cannot replace the built-in Calendar. Check the app's description in the App Store to see if it supports default app settings.

Can I change my default calendar app on an older iPhone?

This feature works on iOS 14 and later. If you have an older iPhone, you cannot change your default calendar app through Settings. You can still read and use other calendar apps, but the built-in Calendar will remain your default.