You can find out the total amount of storage or the number of active Users you currently have within your account as follows.

Log in as the Key User of the account.

Navigate to -> Billing menu, by clicking on the Billing icon on the bottom of the black Navigation bar

Fig 1 - Billing icon

On the top right of the page you will have a summary of your plan, click on the cog icon (see below) to view your Plan Status

Fig 2 - Plan Status

The drop down will inform you of the number of currently active Users, number of active contracts and the total amount of storage.

Note: You can find out about the detail of billing with intelligentcontract in the Understanding Intelligentcontract Billing article