Wondering what is the week number of the current week? You do not need to count week by week. You can add week numbers in Outlook Calendar and you will know the number of the week right away. It is very convenient. However, this will be affected by the way how you define the first day of a week or the first week of the year.
Step 1: Click "File" from the Ribbon;
Step 2: Click "Options" from the left navigation to open "Outlook Options" window;
Step 3: Click "Calendar" from the left navigation;
Step 4: Move down to "Display options" section, and check the box of "Show week numbers in the month view and in the Data Navigator";
Step 5: Click "OK" to close the Outlook Options" window.