Where can I see how much storage capacity I've used with my photos?

In "My account" you can check how much storage capacity you are using:

•     Please login to your Pixum account.
•     Click on "My Pixum" and then on "My account".
•     Click on the link "Information about my pictures". 
•     There you can view how much storage capacity you are currently using for your photos.

We offer a maximum of 1 GB storage capacity for your albums. We do not have a limitation with regards to how long you want to save your photos with us.

Important: With regards to orders the temporary storage capacity is naturally unlimited!

Source: http://www.pixum.no/service/10399-where-can-i-see-how-much-storage-capacity-i-ve-used-with-my-photos.html