Best Free Calendar Apps 2026: 6 Options Compared
Best free Calendar Apps compared: Google Calendar, Notion Calendar, Microsoft Outlook, Thunderbird and 2 more, with free-plan limits, platforms and prices from official pages checked October 24, 2026.
•3 min read•Email, Calendar & Scheduling
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| Google Calendar | Free (Free with a personal Google Account, which can create one appointment booking page; more booking pages need a paid plan) | Web, Android, iOS | Most people and shared schedules | Docs only |
| Notion Calendar | Free (Product page says to get it free; no limits or paid tiers are shown) | macOS, Windows, iPhone, Android | Merging several calendars in one view | Docs only |
| Microsoft Outlook | Free (Free Outlook.com mailbox and web app; the desktop client comes with Microsoft 365 plans) | Windows, macOS, iOS, Android, Web | Microsoft account users | Docs only |
| Thunderbird | Free (Free and open-source desktop mail client; no paid plan stated on the about page) | Windows, macOS, Linux | Self-managed desktop calendars | Docs only |
| Proton | Free (Free plan with 1 GB of Mail, up to 5 GB of Drive, 1 encrypted email address and 3 personal calendars); paid from $3.99 per month, billed annually (Mail Plus) | Web, iOS, Android | Privacy-minded personal calendars | Docs only |
| Zoho Calendar | Free (FAQ calls it a free online calendar for individuals and teams; no limits listed) | Web, iOS, Android | Zoho suite users | Docs only |
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Good fit if
- You mostly accept invites from colleagues using Google (Google Calendar is the pick)
- You juggle Google, Outlook and iCloud calendars (Notion Calendar is the pick)
- You want encrypted calendars (Proton is the pick)
- You prefer desktop software without a cloud account (Thunderbird is the pick)
Not ideal if
- You need paid-tier features, uptime guarantees or support that these free plans leave out
A calendar app lives or dies on sync and sharing, so the question is less which one is free and more which ecosystem you already sit in. Google Calendar is the default for anyone with a Google account and works well with other people's invites. Outlook covers the same ground for Microsoft users, and the free Outlook.com version handles personal use. Notion Calendar is a polished front end that merges Google, Outlook and iCloud calendars in one desktop and mobile app, which solves the problem of having three calendars in three places. Thunderbird bundles a calendar into its free open-source mail client, a fit if you want your data under your control. Proton gives a privacy-focused option with three personal calendars on its free plan, and Zoho Calendar suits people already in the Zoho suite. All of these are free for personal use, but the limits differ: Google Calendar caps free users at one appointment page, and Proton restricts storage and calendar counts. Before you move, export your existing calendar as an ICS file so you can import it elsewhere. Then run the new app alongside the old one for a week and check that invites, reminders and recurring events arrive correctly on every device you use.
Google Calendar
Free with a personal Google account, strongest for sharing and invites. The free tier includes one appointment booking page; more need a paid plan.
Price: Free (Free with a personal Google Account, which can create one appointment booking page; more booking pages need a paid plan) (Google Calendar pricing, checked 2026-10-23).
Platforms and license: Web, Android, iOS. Proprietary.
Best for: Most people and shared schedules.
Compare: Google Calendar alternatives
Notion Calendar
Free desktop and mobile front end that merges Google, Outlook and iCloud calendars with scheduling links. It depends on the calendars you connect.
Price: Free (Product page says to get it free; no limits or paid tiers are shown) (Notion Calendar pricing, checked 2026-10-23).
Platforms and license: macOS, Windows, iPhone, Android. Proprietary.
Best for: Merging several calendars in one view.
Compare: Notion Calendar alternatives
Microsoft Outlook
Free Outlook.com calendar with the web app. The desktop Outlook client comes with Microsoft 365, so the free version means the web.
Price: Free (Free Outlook.com mailbox and web app; the desktop client comes with Microsoft 365 plans) (Microsoft Outlook pricing, checked 2026-10-23).
Platforms and license: Windows, macOS, iOS, Android, Web. Proprietary.
Best for: Microsoft account users.
Compare: Microsoft Outlook alternatives
Thunderbird
Free open-source mail client with a built-in calendar, MPL-2.0. Desktop only, so mobile needs a separate app for sync.
Price: Free (Free and open-source desktop mail client; no paid plan stated on the about page) (Thunderbird pricing, checked 2026-10-23).
Platforms and license: Windows, macOS, Linux. MPL-2.0 (open source).
Best for: Self-managed desktop calendars.
Proton
Free plan includes three personal calendars with encryption, alongside 1 GB mail. Fewer sharing features than Google.
Price: Free (Free plan with 1 GB of Mail, up to 5 GB of Drive, 1 encrypted email address and 3 personal calendars); paid from $3.99 per month, billed annually (Mail Plus) (Proton pricing, checked 2026-10-22).
Platforms and license: Web, iOS, Android. Proprietary hosted service.
Best for: Privacy-minded personal calendars.
Zoho Calendar
Free online calendar for individuals and teams with iOS and Android apps. The page lists no limits or paid price.
Price: Free (FAQ calls it a free online calendar for individuals and teams; no limits listed) (Zoho Calendar pricing, checked 2026-10-24).
Platforms and license: Web, iOS, Android. Proprietary.
Best for: Zoho suite users.
Which one to pick
- You mostly accept invites from colleagues using Google: Google Calendar
- You juggle Google, Outlook and iCloud calendars: Notion Calendar
- You want encrypted calendars: Proton
- You prefer desktop software without a cloud account: Thunderbird
Limits of this review
Docs-only for Google Calendar, Notion Calendar, Microsoft Outlook, Thunderbird, Proton, Zoho Calendar: we did not install or run them, so feature claims come from vendor pages. Vendor prices and free limits change; confirm on the linked pricing page before you commit.
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Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing, license and product pages checked between 2026-10-22 and 2026-10-24: Google Calendar, Notion Calendar, Microsoft Outlook, Thunderbird, Proton, Zoho Calendar. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.