Free online ICS to XLS converter

A calendar application may export a meeting schedule as .ics while an older reporting or records system accepts only .xls. Converting the events into worksheet rows makes them sortable, filterable, editable, and easier to archive in Excel.

What the ICS format is

ICS is the filename extension commonly used for iCalendar files, a text-based calendar interchange format defined primarily by RFC 5545. It can contain events, tasks, journal entries, free/busy data, recurrence rules, attendees, reminders, locations, descriptions, categories, and time-zone information.

Microsoft Outlook, Apple Calendar, Google Calendar, Mozilla Thunderbird, and many scheduling systems can create or export ICS files. Common uses include downloading meeting invitations, transferring calendars between applications, and backing up or sharing calendar data.

What the XLS format is

XLS is the binary Microsoft Excel 97–2003 workbook format. A calendar conversion usually creates one event per row and maps values such as summary, start, end, location, organizer, attendees, description, and UID to separate columns.

An XLS workbook supports sorting, filtering, formulas, printing, manual corrections, and basic reporting in Excel and compatible spreadsheet programs. Its main reason for continued use is compatibility with older software; XLS supports fewer features and rows than the modern XLSX format. An XLS worksheet is limited to 65,536 rows and 256 columns.

How to convert the file

For a direct conversion without installing software, use the converter available on 101convert.com:

1. Open the ICS-to-XLS conversion page on 101convert.com.
2. Upload the .ics file.
3. Select XLS as the output format and start the conversion.
4. Download the generated .xls workbook and open it in Excel, LibreOffice Calc, or another compatible spreadsheet program.

Check the resulting columns and several dates after conversion. Calendar fields do not have a universal one-to-one spreadsheet layout, so the converter must flatten nested data such as attendees, recurrence rules, and reminders.

Using a calendar application and Excel

A calendar application that supports CSV export provides a practical local workflow:

1. Import the ICS file into Outlook, Apple Calendar, Thunderbird, or another compatible calendar application.
2. Export the calendar or selected events as CSV, using the application’s calendar export command.
3. Open the CSV in Excel through Data → From Text/CSV, and verify the delimiter, character encoding, and date columns.
4. Save the workbook through File → Save As, selecting Excel 97–2003 Workbook (*.xls).

Do not simply open an ICS file as plain text and save it as XLS. ICS uses structured property lines, parameters, escaped text, and folded lines; treating it as raw text leaves each property unparsed and does not produce reliable event columns.

Local automated conversion

For repeatable local processing, Python can parse VEVENT components and write an XLS workbook. Install the required packages:

python -m pip install icalendar xlwt

Save this as ics_to_xls.py:

from pathlib import Path
from icalendar import Calendar
import xlwt

source = Path("calendar.ics")
target = Path("calendar.xls")

with source.open("rb") as file:
    calendar = Calendar.from_ical(file.read())

workbook = xlwt.Workbook()
sheet = workbook.add_sheet("Events")
columns = ["UID", "Summary", "Start", "End", "Location", "Organizer", "Attendees", "Description"]

for column, name in enumerate(columns):
    sheet.write(0, column, name)

def text_value(component, name):
    value = component.get(name)
    if value is None:
        return ""
    data = getattr(value, "dt", value)
    return data.isoformat() if hasattr(data, "isoformat") else str(data)

for row, event in enumerate(calendar.walk("VEVENT"), start=1):
    attendees = "; ".join(str(item) for item in event.get_all("ATTENDEE"))
    values = [
        text_value(event, "UID"),
        text_value(event, "SUMMARY"),
        text_value(event, "DTSTART"),
        text_value(event, "DTEND"),
        text_value(event, "LOCATION"),
        text_value(event, "ORGANIZER"),
        attendees,
        text_value(event, "DESCRIPTION"),
    ]
    for column, value in enumerate(values):
        sheet.write(row, column, value)

workbook.save(target)

Put calendar.ics beside the script, or change the source and target paths, then run:

python ics_to_xls.py

The script writes one stored VEVENT component per row. It does not expand recurring events into individual occurrences, and it ignores non-event components such as VTODO and VJOURNAL.

Quality and compatibility limits

ICS is a calendar data model, not a flat table. A conversion may combine multiple attendees into one cell, flatten formatted descriptions, omit alarms and attachments, and discard or simplify categories, invitation status, recurrence rules, and custom properties.

Recurring events may be represented by one event with an RRULE rather than by separate records. If each occurrence must become a row, use a converter or calendar application that explicitly expands the recurrence range before export.

Start and end values can be floating local times, UTC values, or times tied to a named time zone. Verify events around daylight-saving changes and compare all-day events separately; some converters represent them as dates while others write midnight date-times. ISO-formatted values written by scripts may also need explicit date formatting before Excel sorts them chronologically.

Large calendars can exceed the XLS row limit; use XLSX or split the output when necessary. Treat uploaded calendars as potentially sensitive because they may contain private appointments, attendee addresses, locations, and descriptions.