Check your SharePoint storage quota

To check the quota of a SharePoint site, you must be the site owner or a site collection administrator.

1. In your site, click Site Contents, and then select Settings.
2. On the "Site Settings" page, under "Site Collection Administration", click Storage Metrics. 

   Your site collection storage quota will appear in the top right corner of the "Storage Metrics" page, along with a breakdown of data usage.

Note:

Files in your Recycle Bin count toward your storage quota. To free up that space, you must empty the Recycle Bin.