How to Convert OST to ICS on Mac? – Robust Solution with Simple Steps

Sarabjeet Kaur | macOS software technology | 4 minutes read | Last updated on September 15th, 2025,

One feasible and reliable program for converting an OST calendar to an ICS (iCalendar) format is Mac OST to ICS Converter. Since ICS is a widely used file format for saving calendar data, many users from all over the world wish to convert their calendars from Offline Storage Table (OST) files. Many email and calendaring applications, such as MS Outlook, Thunderbird, Gmail, Apple Mail, Exchange Server, G Suite, and others, make it simple for users to utilize ICS files.

Reasons to Convert OST to ICS on Mac OS

ICS files work with a range of calendar programs, such as Apple iCal and Google Calendar, while OST files were designed specifically for MS Outlook.
To access your calendar events in apps like Google Calendar or Apple iCal, you need to export your Offline OST files into ICS.
Make a backup of your calendar data so that transferring it to a different program or device will be easier.
Converting your Exchange OST calendars to ICS is a brilliant option if you want to collaborate on a project or share your calendar events with someone else. This is because ICS files are designed to be shared with other users.

Beyond this, there are a number of other reasons why users have to perform these kinds of tasks. Once we have read the reasons, let’s proceed to the solution to finish this work.

How to Convert OST to ICS on Mac Using Top-Rated Approach?

There are dual methods for moving OST files into ICS file format: manual and professional. However, you must first export the Offline OST file to a PST file, which needs to be converted in Outlook, in order to carry out this procedure manually. The calendar export feature enables the user to import data into an ICS format after exporting the PST file.

The manual conversion of OST into ICS is very time-consuming. Errors and data loss are also frequent. As well, when converting OST calendars to ICS (iCalendar) manually, batch processing is not available; instead, the user must convert each file individually. It is generally not recommended to manually convert the OST calendar to ICS on Mac due to these reasons.

So, it’s advised to utilize the expert and reliable third-party tool to perform this conversion task.

Highly Advised Mac OST to ICS Tool

While keeping all the needs of users, we’ve designed MacMister Mac OST Converter Tool. With this software, users can efficiently and successfully convert multiple OST calendars in ICS file format without any restrictions. It lets users perform this migration in batch or selectively as per the needs.

The tool preserves all the properties when exporting OST files into ICS calendars. You’ll not face any kind of problem while utilizing the program. Moreover, you can carry out this process by following the easy steps listed below:

Firstly, download & launch OST Converter for Mac Tool on your Mac device.

Add OST Files/Folder on the program panel by utilizing two options such as Add Files or Add Folder. Click Next.

The app will provide a list of OST Files along with Checkboxes. And, if necessary, the Checkbox will assist users in converting the particular OST file in ICS calendar on Mac PC. To proceed, hit the Next tab.

Press on Select Saving Option, then pick ICS from the drop-down menu. To begin the migration process, hit the Export tab.

As soon as the conversion begins, the tool will display a Live Conversion Window with the current export status of the Offline OST files.

Eye-Catching Features of Mac OST to ICS Tool

Batch Conversion: This program allows you to convert countless OST files at once into the ICS calendars in bulk. To complete the conversion, you don’t have to look over each OST file individually.

Selective Migration: If you wish to migrate only selected Exchange OST emails into ICS format, it’s possible. This utility enables users to opt only those OST emails they wish to move.

Easy to Use UI: The program’s UI is quite user-friendly. It can also be used without difficulty by a novice user.

Several Saving Options: The tool can effectively import an OST file to ICS and saving options like OST to PST, PDF, EML, MSG, HTML, TXT, DOC, MBOX, Gmail, Office 365, IMAP, Outlook.com, Thunderbird, etc.

Mac Supportive: It works with every version of the Macintosh Operating System, both old and new. It is compatible with Mac OS X 14, 13, 12, 11, 10.15, 10.14, 10.13, and previous versions.

Conclusion

In today’s post, we’ve covered how to convert OST to ICS on Mac OS with all elements. Here, we’ve offered a verified and quick solution that allows you effortlessly convert OST calendar to ICS on Mac OS. You can also download the free trial edition and explore the features and working process of the software for free.