To view the item count and storage size of Microsoft 365 user account based on the usage for Exchange (Outlook), OneDrive, and SharePoint, follow the instructions below:

1. Login to Microsoft 365.
   
   
2. Go to the Microsoft 365 admin center.
   
   
   
3. On the Microsoft 365 admin center, click Show all then click the dropdown arrow for the Reports and select Usage.
   
   
   
4. On the Usage screen, scroll down and click the View more button of the usage report that you want to view.
   
   
   
   
5. For Exchange, click the View More button under Email activity, then go to Mailbox usage.
   
   
   Highlighted columns are Item count and Storage used (MB).
   
   • Item count - number of mailbox items in Outlook per Microsoft 365 user account
     
   • Storage used (MB) - storage used in MB size per Microsoft 365 user account
     
     
     
6. For OneDrive, click the View Mode button under OneDrive files.
   
   
   
   Highlighted columns are Files and Storage used (MB).
   
   • Files - number of files in OneDrive per Microsoft 365 user account
     
   • Storage used (MB) - storage used in MB size per Microsoft 365 user account
     
     
     
7. For SharePoint, click the View More button under SharePoint files then go to Site usage.
   
   
   
   Highlighted columns are Files and Storage used (MB).
   
   • Files - number of files in SharePoint per Microsoft 365 user account.
     
   • Storage used (MB) - storage used in MB size per Microsoft 365 user account.