# Sync Outlook Into Google Calendar: Free Steps and Where They Stop > How to sync Outlook into Google Calendar for free, link Google to Outlook and Apple Calendar, and the point where one-way links start causing double bookings. _Source: https://professionalstoolkit.com/articles/sync-outlook-and-google-calendar — The Professional's Toolkit · updated October 2026_ --- To sync Outlook into Google Calendar for free, publish your Outlook calendar as an ICS link, then add that link in Google Calendar with Add other calendars and From URL. Going the other way, copy Google's secret iCal address and subscribe to it in Outlook. Both links are one-way and read-only, and they refresh on the receiving provider's schedule. That works for seeing one calendar inside the other. It does not stop double bookings once clients book you through a link, because the copy can run hours behind. **24+ hours** — How long Microsoft says a subscribed calendar can take to refresh - **~3 hours** — Outlook.com's usual refresh target for a subscribed calendar - **1 way** — Each ICS link copies one calendar in one direction, read-only - **1 vs 6** — Calendars Calendly checks on Free vs Standard ## Why two calendars cause double bookings Most double bookings are not a scheduling mistake. They happen because your day lives in two places. A day job, a client, or a school runs on Microsoft 365, while your own business runs on Google. Each calendar only knows its own events. So a free slot in Google may already be taken in Outlook, and nobody sees it until two people show up. The free fix is to make one calendar *show* the other. The real fix is to make whatever takes bookings *check* both. Our guide to [how to avoid double booking](/articles/how-to-avoid-double-booking) covers the wider method. Before you start, decide which direction you need. If clients book you through Google Calendar, Outlook events must flow into Google. If your employer or team looks at Outlook to find you, Google events must flow into Outlook. Many people need both, which means two separate links, one in each direction. Neither link edits the other side. You can view the copied events, but you change them only where they were created. ## How to sync Outlook into Google Calendar, step by step This route uses the publishing feature in Outlook.com and the subscribe-by-URL feature in Google Calendar. Microsoft's steps for publishing are short [1]. Microsoft documents these steps for Outlook.com; for a Microsoft 365 work calendar it points to separate sharing settings your admin controls. 1. In Outlook, open Calendar view and select **Settings > Calendar > Shared calendars**. 2. Under **Publish a calendar**, choose the calendar and how much detail people can see. 3. Select **Publish**, then copy the **ICS** link (not the HTML link, which only opens in a browser). 4. On a computer, open Google Calendar. Next to **Other calendars**, click **Add other calendars**, then **From URL** [2]. 5. Paste the ICS link and click **Add calendar**. It appears under Other calendars. Do this on a computer. Google says you can't subscribe to a new calendar from the Google Calendar app for Android, iPhone, or iPad. > 💡 **Publish with the least detail:** Anyone with a published calendar link can open it. If you only need busy blocks in Google, choose the least detailed option when you publish. Two settings matter here. The detail level you pick in step 2 decides what Google shows. Choose full details only if nobody else will ever see the link, because a published calendar can be opened by anyone who has the address. If you only need to block time, the least detailed option is safer. To stop sharing later, go back to Shared calendars and select **Unpublish** to stop sharing the published link. ## The other direction: Google Calendar into Outlook Microsoft documents this route for Outlook.com and Outlook on the web [3]. On a computer, open Google Calendar and click **Settings** in the top right. Under **Settings for my calendars**, click the calendar you want, then click **Integrate calendar**. Copy the link in the **Secret address in iCal format** section. Then switch to Outlook, select **Add calendar**, choose **Subscribe from web**, paste the address, and select **Import**. The Google calendar now sits next to your Outlook one, and it updates on its own. Treat that secret address like a password. Google says only you should know it and tells you not to share it. If you share it by accident, click **Reset** to create a new one. On a work or school Google account you may not find the secret address at all. Google says your admin might have changed the sharing settings for your calendar, so the fix is to ask your admin for help. Avoid the import option for this job. Microsoft's own notes are clear: an imported .ics file is a snapshot and never refreshes, even when the owner changes an event. It suits events that never change, like tide tables or phases of the moon. It does not suit a working calendar. ## How to sync Google Calendar with Apple Calendar Apple Calendar is the easy case, because it can hold your Google account directly instead of a read-only link. On a Mac, open the Calendar app, choose **Calendar > Add Account**, select Google, click **Continue**, and follow the sign-in prompts [4]. Each account then shows separately in the sidebar. Apple suggests setting up your iPhone and iPad with the same account so calendars stay current across devices. This is a real sync, not a subscription. Google says that when an app lets you add your Google Account, you can add and edit events from either Google Calendar or that app. Outlook can be added to Apple Calendar the same way if your provider supports it, so a Mac can show all three calendars in one view. That helps you see conflicts. It still does not tell a booking page which hours are taken. > ⚠ **Import is not sync:** Importing an .ics file adds a one-time snapshot that never refreshes. Use Subscribe from web or From URL so changes keep flowing. ## A mini example: one consultant, two calendars Dana coaches clients two days a week and works three days for a firm that runs on Microsoft 365. Her client calls live in Google Calendar, and her firm meetings live in Outlook. She publishes her Outlook calendar with the least detail and adds the ICS link to Google with From URL. Now her Google week shows the firm meetings as busy blocks. On Monday her manager adds a Thursday workshop at 10 a.m. The copy in Google does not show it yet. On Tuesday a client books Thursday at 10 a.m. Both bookings are now real. Nothing was set up wrong. The subscription simply had not refreshed, and the client could only see Google. ## When the free sync stops working: the threshold The free route breaks on timing. Microsoft says a subscribed calendar refreshes automatically, but the update can take more than 24 hours, even though Outlook.com aims for roughly every three hours [3]. How often Google picks up your published Outlook calendar depends on Google, and Microsoft does not promise a number. For looking at your own week, a lag is harmless. For a calendar that strangers book against, it is the gap Dana fell into. So the threshold is concrete. The free sync is fine while you set every meeting yourself and glance at both calendars first. It stops being enough on the day you **share a booking link**, or when changes land in Outlook less than a day before the slot. It gets worse with three or more calendars, since each pair needs its own link, and with a team, since every person repeats the setup. The fix is not a better copy. It is a scheduler that connects to each calendar directly and checks all of them before it offers a time. How many calendars it checks is the split that matters. Our [calendar sync tools guide](/articles/calendar-sync-tools) compares every option. Three that fit the two-calendar case: ### Cal.com — solves this Connect Outlook/Office 365, Google and Apple calendars; Cal.com checks every selected calendar for conflicts so bookers only see free slots, and writes new bookings to the calendar you choose. - Where it stops: Per-event-type conflict settings apply to individual event types, not team event types. - Plan: Free (unlimited calendars) - More: [Cal.com](https://professionalstoolkit.com/tools/cal-com) ### Calendly — solves this Connect Outlook and Google; Calendly checks the connected calendars for busy times and adds each new meeting to one main calendar. Outlook events marked Busy, Tentative or Away block you by default. - Where it stops: Free checks one calendar, so a separate work or personal calendar goes unchecked. - Plan: Standard (up to six calendars per user) - How Calendly does it: [Calendar connections and plans](https://professionalstoolkit.com/articles/calendly-integrations) - More: [Calendly](https://professionalstoolkit.com/tools/calendly) ### TidyCal — solves this Connect Google and Microsoft 365 calendars; TidyCal reads busy time from every calendar with Reading on and writes bookings back. Google and Microsoft changes arrive within minutes. - Where it stops: Free connects one calendar, and its background sync pauses after 90 idle days. - Plan: Individual Lifetime (10 calendars) - How TidyCal does it: [Which calendars connect, by plan](https://professionalstoolkit.com/articles/tidycal-integrations) - More: [TidyCal](https://professionalstoolkit.com/tools/tidycal) Calendly's Free plan checks one calendar, which is exactly the Dana trap; [Calendly's calendar integrations](/articles/calendly-integrations) shows how Standard covers up to six. TidyCal reads busy time from every calendar with Reading turned on, and its [calendar integrations guide](/articles/tidycal-integrations) lists which plan allows how many. Whichever you pick, connect both Outlook and Google. A calendar that is not connected is never checked. > 💡 **Connect every calendar you use:** A scheduler only checks the calendars connected to it. Connect Outlook and Google directly instead of relying on a subscribed copy. ## FAQ **Can I sync Google Calendar with Outlook both ways for free?** Not with links. Each ICS subscription is one-way and read-only, so you need one link in each direction and you edit events only where they were created. **Why is my Outlook calendar not updating in Google Calendar?** Google Calendar refreshes a calendar added From URL on its own schedule, not instantly. Microsoft says how often a published ICS calendar syncs depends on the recipient's provider, so a change made in Outlook can take hours to show in Google. **How do I sync my calendar on iPhone with Google?** On the iPhone, open Settings, tap Apps, then Calendar, then Calendar Accounts, and tap Add Account. Choose Google and sign in; your Google calendars then appear in the Calendar app. If you also use a Mac or iPad, Apple suggests adding the same account there so calendars stay up to date. **How do I hide a subscribed calendar in Google Calendar?** On a computer, open Google Calendar and, under Other calendars, uncheck the calendar you want to hide. ## The bottom line You can sync Outlook into Google Calendar for free with two short steps: publish the Outlook calendar as an ICS link and add it in Google with From URL, or subscribe to Google's secret iCal address in Outlook. For Apple Calendar, add the Google account itself. Those links are one-way, read-only, and can lag by more than a day. Keep them for viewing. The moment other people book your time, let a scheduler connect both calendars directly and check them before it offers a slot. ## Sources [1] Microsoft Support — https://support.microsoft.com/en-us/outlook/share-your-calendar-in-outlook-com (Nov 2026) [2] Google Calendar Help — https://support.google.com/calendar/answer/37100?hl=en&co=GENIE.Platform%3DDesktop (Nov 2026) [3] Microsoft Support — https://support.microsoft.com/en-us/outlook/import-or-subscribe-to-a-calendar-in-outlook-com-or-outlook-on-the-web (Nov 2026) [4] Apple Support — https://support.apple.com/guide/calendar/add-or-delete-calendar-accounts-icl4308d6701/mac (Nov 2026)