Hello there, if you know your number of licensed users, you can use this calculation. If you have a need to purchase additional storage you can review this documentation: https://docs.microsoft.com/en-us/stream/storage-add-on
"When your organization purchased Microsoft Stream, you received 500 GB of base storage and an additional 0.5 GB of storage per licensed user."
@NealM thanks for the reply. I'm sure we don't in reality, but we have unlimited listed next to a number of our O365 products available to staff and students and we don't pay for these. Therefore it's hard to do any math where one of the values is unlimited. I'll ask via our education rep at MS and see what comes back.
