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Outlook shared calendar or SharePoint calendar for a team

Short answer: use an Outlook shared calendar when the point is who is busy when. Use a SharePoint calendar when each event needs columns, such as Owner, Status or Room, that you can filter and report on. On classic SharePoint calendars you can also overlay an Exchange calendar, up to four calendars in all. On a modern site, Microsoft points to the Group calendar web part instead.

What an Outlook shared calendar gives you

Microsoft's page "Share your calendar in Outlook on the web" names five levels you can give a person:

To share: open Calendar, select Share on the toolbar and choose the calendar, enter the person's name or email address, choose a level, and select Share. Exact names may differ on your screen.

Good fit: team out-of-office, who is at which site, meeting rooms where the only question is "free or busy."

What a SharePoint calendar gives you

A SharePoint calendar is a list shown in a Calendar view. Each event is a row, so you can add your own columns. Microsoft says any list that has a date column can be viewed in calendar format. Our advice, not a Microsoft rule: add Choice columns such as Event type and Owner, and a Status column with numbered values like 1 Planned and 2 Confirmed. Then save a view for each team.

Good fit: a calendar that is also a log, such as install dates, audits, or deliveries, where you want to filter by owner or count events by type.

How to choose, in four questions

  1. Do people need to see each other's free and busy time? Outlook.
  2. Do events need columns you can filter on? SharePoint.
  3. Do events need invites and reminders on each person's calendar? Outlook.
  4. Should the calendar live on a team site page, next to other tracker content? SharePoint, or the Group calendar web part on a modern site.

Show an Outlook calendar on the SharePoint calendar (overlay)

Microsoft's overlay page lists SharePoint Server 2016, 2013 and 2010 under Applies To. Use these steps only on a classic calendar.

Microsoft's overlay page says: "In all, you can add up to four Exchange or SharePoint calendars." Steps from that page for an Exchange calendar:

  1. Open the SharePoint calendar and go to the Calendar tab.
  2. Select Calendar Overlays.
  3. On the Calendar Overlay Settings page, select New Calendar.
  4. Enter a name and select Exchange.
  5. Select Find to fill in the Outlook Web Access and Exchange Web Service URLs. If Find does not work, enter them yourself.
  6. Optionally select Always Show.
  7. Select OK twice.

Three limits Microsoft states on that page:

If the overlay does not appear, see "SharePoint calendar overlay not showing".

What happens when the owner leaves

Microsoft's overlay page says the Exchange overlay uses the signed-in person's credentials, so an overlay is tied to a person. Our advice, not a Microsoft rule:

  1. Keep a short written list of who owns each calendar and each overlay.
  2. Name two owners for the SharePoint site, so the calendar list is not tied to one account.
  3. Before anyone leaves, open the overlay settings and check which calendars are in it.
  4. For the SharePoint list, see "Power Automate flow owner left the company" if a flow adds events.

Sync between the two

Microsoft's pages here describe no built-in sync between an Outlook shared calendar and a SharePoint calendar list. If you need events in both, a Power Automate flow is one option, with a loop guard so the flow does not trigger itself. See "Power Automate flow triggers itself". Keep the flow small: one trigger, one create-event action, and a Sent flag (a Yes/No column the flow checks is not Yes before it acts, then sets to Yes).

Microsoft 365 group calendar

Microsoft's overlay page says SharePoint offers a modern experience with Microsoft 365 group calendars. The Group calendar web part puts a Microsoft 365 group calendar on a SharePoint page. Microsoft's web part page says it works only on Team sites, shows up to 10 events, and shows only events scheduled up to 6 months ahead. To add it: select Edit on the page, open the toolbox, add Group calendar, then pick the group in the property pane. Exact names may differ on your screen.

When to get help

You can build all of this yourself in Microsoft 365. If you would rather have it built and tested for your team, I do that. A tracker like this is a fixed price: $5,000 for one, built in 2 weeks. See "What a SharePoint tracker costs to build". Bring one example of the problem to a free call.

Tell me what's still manual

I am Al Davies. I run 250 High Street LLC and build SharePoint trackers and Power Automate flows for operations teams. I work remotely. The first call is free, and I will not try to sell you anything.

See trackers I built: Tools I built

FAQ

What is the difference between an Outlook shared calendar and a SharePoint calendar?

Outlook shares free and busy time and event details with people you choose. A SharePoint calendar is a list with columns you can filter.

Can I show an Outlook calendar in SharePoint?

On a classic SharePoint calendar, Microsoft's overlay page describes overlaying your own Exchange calendar, up to four calendars in all. The page applies to SharePoint Server. On a modern site, Microsoft points to the Group calendar web part.

Can I overlay someone else's Outlook calendar on a SharePoint calendar?

Microsoft says you can only overlay your own Exchange calendar, using the signed-in user's credentials.

What permission levels does an Outlook shared calendar have?

Can view when I'm busy, Can view titles and locations, Can view all details, Can edit, and Delegate.

How many calendars can I overlay on a SharePoint calendar?

Microsoft says up to four Exchange or SharePoint calendars in all.

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