1. Sign in to your Office 365 admin account.

    infoYou must be a global administrator in Office 365 or an Exchange, SharePoint, OneDrive for Business administrator, or reports reader to see Office 365 reports.
  2. Click App Launcher ( ) on the upper left, and then click Admin ( ).

  3. In the main menu, go to Reports > Usage.

  4. From the Select a report dropdown list:

    • Click Exchange > Mailbox usage, then click Storage, and then click the rightmost point in the chart.

      This will show you the total amount of storage used by Exchange account mailboxes in your organization. (See details on the Exchange mailbox usage reports.)

    • Click OneDrive > Usage, then click Storage, and then click the rightmost point in the chart.

      This will show you the total amount of OneDrive storage used by all user accounts in your organization. (See details on the OneDrive usage reports.)

    • Click SharePoint > Site usage, then click Storage, and then click the rightmost point in the chart.

      This will show you the total amount of storage used by SharePoint account sites in your organization. (See details on the SharePoint site usage reports.)

  5. Calculate the average storage use per account as follows: