The Proton Calendar Insider’s Guide
Everything we know about Proton Calendar in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
Proton Calendar
The Insider’s Guide
End-to-end encrypted calendar from the maker of Proton Mail
Every plan, grade, refund rule and rival among calendar and scheduling apps, read from Proton Calendar’s own pages.
Made by Proton AG · checked Oct 5, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from Proton Calendar’s own pages, its app-store listings and our grades. Every fact in it is on Proton Calendar’s page too, where it is kept up to date. Checked Oct 5, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
2.6
GPA, above 30 of the 74 other calendar and scheduling apps we grade
Proton Calendar is an encrypted calendar from Proton AG in Switzerland. Event titles, descriptions, locations and attendees are end-to-end encrypted so that Proton cannot read them. It is included free with a Proton account, limited to 3 calendars; calendar sharing, booking pages and up to 25 calendars come with Proton's paid plans, since Calendar is not sold on its own.
To get you started, here are 9 things to know about Proton Calendar, taken from its own pages and our grades.
On a computer there's no Calendar app of its own either: you reach it through the Proton Mail app.
- 1
Best for a calendar your provider can't read
There are no tasks, no API, and the Linux app is a beta.
- 2
Paid plans start at $3.99 a month
As its pricing page puts it: $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
- 3
There is a free plan
Proton Free: 3 personal calendars with end-to-end encryption and event invitations. No calendar sharing or booking pages, and the desktop app is a 14-day trial.
- 4
It runs on 6 platforms
Web, macOS, Windows, Linux, iOS and Android.
- 5
End-to-end encrypted events
An event's title, description, location and attendees are encrypted on your device. Events received from people on other calendar services are stored with zero-knowledge encryption.
- 6
Appointment booking pages
Publish a booking page that shows only the times you choose and syncs with your calendars to prevent double bookings. Confirmed meetings can include a Proton Meet link. Paid plans only.
- 7
Calendar sharing
On paid plans, share a calendar by link or by inviting people directly, showing either full event details or only your availability.
- 8
A 2.6 GPA, above 30 of 74
That is against the other calendar and scheduling apps we grade, on value, the free plan, features, ease of use and platforms.
- 9
Keep it
The plain part of Proton Calendar you could make: calendar. What surrounds it you could not. The 4 things listed below take a company, not a weekend.
Proton Calendar at a glance
- Pricing
- Free plan, from $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly
- Free plan
- Yes
- Free trial
- None stated
- Runs on
- Web, macOS, Windows, Linux, iOS, Android
- Made by
- Proton AG
- Category
- Calendar & Scheduling
- Our grade
- 2.6 GPA, good
- Store rating
- 4.1 on the App Store, 1,507 ratings
The report card
Best for a calendar your provider can't read
Proton Calendar encrypts event titles, places and guests before they leave your device, and it's free with a Proton account for 3 calendars. Sharing and booking pages need a paid plan, you can't buy Calendar on its own, only bundled with mail from $3.99 a month billed yearly, and Mail Plus includes just 1 booking page. There are no tasks, no API, and the Linux app is a beta.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | B | Mail Plus is $3.99 a month billed yearly, inside this category's lowest quarter, and it brings encrypted email, 15 GB and 10 addresses with it. The odd part: there's no Calendar-only plan, so you're buying mail whether you want it or not. |
| Free plan and trial | B | Free gives 3 encrypted calendars and invitations with no time limit. No calendar sharing and no booking page, though, and on a free account the desktop app is a 14-day trial. |
| Features | C | The basics, encrypted: repeating events with several reminders, day, week and month views, imports through Easy Switch, invitations handled inside Proton Mail. The gaps are the listing's own. Sharing and booking pages are paid, Mail Plus includes just 1 booking page, and there are no tasks. |
| Ease of use | C | 4.1 from about 1,500 App Store ratings, which is low for a calendar. On a computer there's no Calendar app of its own either: you reach it through the Proton Mail app. |
| Platforms and integrations | B | Web, Mac, Windows, Linux, iPhone and Android. What it connects to is all its own, though: Proton Mail and Proton Meet, no API, and the Linux app is beta. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who Proton Calendar is for
- Fits if you want your event details unreadable to the company storing them
- Works for people already on Proton Mail who want invitations handled in the inbox
Who it is not for
- Skip it if you want to share a calendar for free, because sharing needs a paid plan
- Tight if you're staying free and juggle more than 3 calendars
- Not for you if you want to pay for a calendar alone, since the paid features come bundled with mail
- Tight if you take bookings: Mail Plus and Unlimited include 1 booking page, and 25 need Workspace at $12.99 a user
- Watch out: on a computer it runs through the Proton Mail app, a 14-day trial on free accounts, and the Linux app is beta
Good to know
Good for
- People who want event details kept unreadable to the provider
- Existing Proton Mail users who want invitations handled in the inbox
- Privacy-focused organizations standardizing on Proton's business suite
Worth knowing
- Proton Free allows 3 personal calendars; Mail Plus and higher plans allow 25.
- Calendar sharing and booking pages need a paid plan, and Mail Plus and Proton Unlimited include only 1 booking page.
- Calendar has no subscription of its own: paid features come with Mail Plus, Proton Unlimited or a business plan.
- Desktop use is through the Proton Mail app for Mac, Windows and Linux, a 14-day trial on free accounts; the Linux app is labeled beta.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
$3.99
A month to start. There is a free plan too
Proton Calendar has a free plan. Paid plans start at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
The odd part: there's no Calendar-only plan, so you're buying mail whether you want it or not.
Proton Free
$0
3 personal calendars, end-to-end encryption, and sending and receiving invitations.
Mail Plus
$3.99
per month, billed every 12 months ($47.88); $4.99 billed monthly
25 personal calendars, calendar sharing and 1 booking page, plus 15 GB of storage and 10 email addresses.
Proton Unlimited
$9.99
per month, billed every 12 months ($119.88); $12.99 billed monthly
The same calendar features as Mail Plus, bundled with 500 GB of storage and Proton's VPN, password manager and cloud storage.
Workspace Standard
$12.99
per user / month, billed every 12 months ($155.88)
Business suite with 25 calendars and 25 booking pages per user, 1 TB of storage per user and 15 custom email domains.
Workspace Premium
$19.99
per user / month, billed every 12 months ($239.88)
Everything in Workspace Standard, plus 3 TB of storage per user, 20 custom email domains and data retention policies.
Enterprise
Custom
All Proton services in a customizable package with a dedicated account manager; priced through sales.
The free plan
Proton Free: 3 personal calendars with end-to-end encryption and event invitations. No calendar sharing or booking pages, and the desktop app is a 14-day trial.
Read from proton.me on Oct 5, 2026.
Ways to pay less
Annual discount
20% off Mail Plus on the 12-month plan
Proton's pricing page lists Mail Plus at $3.99 a month when billed every 12 months ($47.88), against $4.99 billed monthly. Proton Unlimited is $9.99 instead of $12.99.
Stated on proton.meEducation
Student discount for the first 12 months
Students verified through Student Beans get 50% off Mail Plus and 62% off Proton Unlimited for the first 12 months; the plan then renews at the regular price.
Stated on proton.meNonprofit
Reduced pricing for registered nonprofits
Registered nonprofits can request discounted pricing on Proton's business plans from the sales team. No fixed percentage is published.
Stated on proton.me
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
6
Places it runs: Web, macOS, Windows, Linux, iOS and Android
End-to-end encrypted calendar from the maker of Proton Mail. Here is what it does, as its own site describes it, and what it covers: open source, end-to-end encrypted, calendar, booking links.
Web, Mac, Windows, Linux, iPhone and Android.
- End-to-end encrypted events
- An event's title, description, location and attendees are encrypted on your device. Events received from people on other calendar services are stored with zero-knowledge encryption.
- Appointment booking pages
- Publish a booking page that shows only the times you choose and syncs with your calendars to prevent double bookings. Confirmed meetings can include a Proton Meet link. Paid plans only.
- Calendar sharing
- On paid plans, share a calendar by link or by inviting people directly, showing either full event details or only your availability.
- Works with Proton Mail
- Send invitations from a Proton Mail address, manage them without leaving the inbox, and add events received by email, such as flights or meetings, to the calendar.
- Recurring events and reminders
- Events can repeat daily, weekly, monthly or on a custom pattern, with several reminders or email alerts each. Views switch between day, week and month.
- Import and calendar subscriptions
- The Easy Switch tool imports existing calendars from other providers, and you can subscribe to calendars that other people keep on a different service.
Where it runs
- Web
- macOS
- Windows
- Linux
- iOS
- Android
What it works with
- Proton Mail
- Proton Meet
Proton Calendar is made by Proton AG.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
30/74
Other calendar and scheduling apps it is graded above
Proton Calendar's GPA of 2.6 is higher than 30 of the 74 other calendar and scheduling apps we grade, and level with 13.
It stands best on free plan and trial (B, above 41 of 74) and worst on ease of use (C, above 0).
Its paid plans start at $3.99 a month, against a middle price of $6 for the category: 17 of the 52 others that charge start lower.
On features, ease of use and platforms it scores 2.3 out of 4. 16 tools score higher and cost less.
Each grade against the category
Every bar is all 75 calendar and scheduling apps we grade, cut by the letter each got. Proton Calendar’s own letter is outlined.
- BValue for moneyAbove 37 of 74
- BFree plan and trialAbove 41 of 74
- CFeaturesAbove 3 of 74
- CEase of useAbove 0 of 74
- BPlatforms and integrationsAbove 25 of 74
Price against what you get
Each dot is one of 67 calendar and scheduling apps. Further left costs less; higher up scores better on features, ease of use and platforms. Proton Calendar is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
The plain part of Proton Calendar you could make: calendar. What surrounds it you could not. The 4 things listed below take a company, not a weekend.
It costs $47.88 a year. Proton Calendar is open source, so there is a third way: take its code and run it yourself.
What you could make
- Calendar: an app builder makes this well.
What you could not
- Booking pages that read and write other people's calendars and send the emails.
- Apps for macOS, Windows, Linux, iOS and Android that stay in step with each other.
- End-to-end encryption done properly.
- Sharing with other people, which means accounts and invitations.
What this rests on. Proton Calendar’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
Tuta Calendar, Google Calendar, Apple Calendar, Fantastical and Notion Calendar
The 5 tools Proton Calendar is most often weighed against, with where each one differs from it.
- 2.4GPA
Tuta Calendar
Free plan · from €3/mo
End-to-end encrypted calendar bundled with Tuta Mail.
- Proton Calendar also covers booking links.
- 3.4GPA
Google Calendar
Free plan · from $7/mo
Online calendar from Google, free with a personal account.
- Only Proton Calendar lists macOS, Windows and Linux apps.
- Proton Calendar is open source and end-to-end encrypted, according to its own site.
- Google Calendar also covers tasks.
- 3.2GPA
Apple Calendar
Free
Free built-in calendar for iPhone, iPad, Mac and iCloud.com.
- Only Proton Calendar lists Windows, Linux and Android apps.
- Proton Calendar is open source and end-to-end encrypted, according to its own site.
- Proton Calendar also covers booking links.
- 2.4GPA
Fantastical
Free plan · from $4.75/mo
Calendar and tasks app for Apple devices, Windows and Googlebook.
- Only Proton Calendar lists a web app.
- Only Proton Calendar lists Linux and Android apps.
- Proton Calendar is open source and end-to-end encrypted, according to its own site.
- 3.6GPA
Notion Calendar
Free
Free calendar app that connects to Notion databases.
- Only Proton Calendar lists a Linux app.
- Proton Calendar is open source and end-to-end encrypted, according to its own site.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
14
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is Proton Calendar free?
Proton Calendar has a free plan. Proton Free: 3 personal calendars with end-to-end encryption and event invitations.
How much does Proton Calendar cost?
Proton Calendar lists 6 plans. Proton Free: $0.
What platforms does Proton Calendar work on?
Proton Calendar is available on Web, macOS, Windows, Linux, iOS and Android.
Does Proton Calendar offer any discounts?
Proton Calendar publicly lists the following: 20% off Mail Plus on the 12-month plan; Student discount for the first 12 months; Reduced pricing for registered nonprofits.
How is Proton Calendar rated?
Proton Calendar's iPhone and iPad app averages 4.1 out of 5 from 1,507 ratings on the App Store in the United States, as read on Oct 5, 2026.
Is Proton Calendar open source?
Yes. Proton Calendar is open source, according to its own site.
Is Proton Calendar end-to-end encrypted?
Proton Calendar describes itself as end-to-end encrypted on its own site.
What does Proton Calendar integrate with?
Proton Calendar's listing names Proton Mail and Proton Meet. A listing names up to eight integrations, so it may connect to more.
Does Proton Calendar have a student discount?
Student discount for the first 12 months. Students verified through Student Beans get 50% off Mail Plus and 62% off Proton Unlimited for the first 12 months; the plan then renews at the regular price.
Who makes Proton Calendar?
Proton Calendar is made by Proton AG.
What are the alternatives to Proton Calendar?
The closest alternatives to Proton Calendar in our directory are Tuta Calendar, Google Calendar, Apple Calendar, Fantastical and Notion Calendar.
How does Proton Calendar compare with other calendar and scheduling apps?
Proton Calendar's GPA of 2.6 is higher than 30 of the 74 other calendar and scheduling apps we grade, and level with 13.
Is Proton Calendar good value for money?
ToolGPA grades Proton Calendar B for value for money. Its paid plans start at $3.99 a month, against a middle price of $6 for the category: 17 of the 52 others that charge start lower.
Could I make my own version of Proton Calendar?
The plain part of Proton Calendar you could make: calendar. What surrounds it you could not.
Where this guide comes from
The prices, plans, platforms and features were read from Proton Calendar’s own pages on Oct 5, 2026, and the grades were given on Oct 10, 2026. Graded from this listing, whose facts were read from Proton's own pages on 5 October 2026, and its App Store rating. Also tested with a demo account on 2026-06-17.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Proton AG. Prices change, so check proton.me before you buy.
- proton.me/calendar
- proton.me/mail/pricing?product=calendar
- proton.me/business/plans?product=calendar
- proton.me/support/proton-plans
- proton.me/calendar/features
- proton.me/calendar/security
- proton.me/calendar/download
- proton.me/business/calendar
- proton.me/business/calendar/appointment-scheduling
- proton.me/support/calendar-appointment-scheduling
- proton.me/student
- proton.me/business/nonprofit-discount
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
3,189
Tools graded, in 94 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
3,189
tools graded
94
categories
426
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- Proton Calendar, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/proton-calendar
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "Proton Calendar: The Insider's Guide", checked Oct 5, 2026. https://toolgpa.com/tools/proton-calendar
Know someone choosing between calendar and scheduling apps?
Send them this guide: toolgpa.com/tools/proton-calendar/guide
ToolGPA elsewhere: youtube.com/@toolgpa
See our other guides
The best-graded calendar and scheduling apps after Proton Calendar, each with an Insider's Guide of its own.
- Calendar & Scheduling Insider's GuideEvery one of the 75 calendar and scheduling apps we grade, compared
- Notion Calendar Insider's GuideFree calendar app that connects to Notion databases3.6 GPA
- Google Calendar Insider's GuideOnline calendar from Google, free with a personal account3.4 GPA
- World Time Buddy Insider's GuideVisual time zone converter and world clock for planning calls3.4 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what Proton Calendar’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Proton Calendar is a trademark of its owner, and this guide is not made, paid for or approved by Proton AG. Prices and plans change: check proton.me before you buy.