How usage is calculated

Usage refers to your consumption of Metered RAM and storage Skytap resources. This article discusses how usage is calculated in your account.


Usage metrics

Skytap uses several metrics to report usage:

Metric Description
Concurrent Metered RAM The highest amount of Metered RAM A unit of measurement used to calculate VM usage, based on the amount of RAM (in GB) for a VM. To learn more, see How usage is calculated. that has been running at one time.
Metered RAM is calculated based on the amount of RAM, in GB, dedicated to running VMs
Metered RAM hours 1 RAM hour equals 1 GB RAM running for 1 hour.
RAM usage is charged by the minute.
For example if you run a VM from 10:00 AM to 10:02 AM, it would result in two minutes of usage. If you ran the same VM again from 10:05 AM to 10:15 AM, you’d be charged for an additional 10 minutes of usage.
Storage Total storage use includes:
  • The cumulative space allocated to the virtual disks in your environments and templates. For example, if you have 20 VMs with 30 GB of virtual disk space each, your cumulative VM storage use is 600 GB.
  • The cumulative amount of space consumed by the assets in your accounts.

Import and export files aren't added to your storage totals.

Cumulative storage
(GB hours)
An aggregate of the amount of storage used on a hourly basis during a billing cycle.
Public IP addresses
  • Usage shown on the Settings page includes the number of attached and unattached public IP addresses in your account. The Manage Public IP Addresses page displays a list of these addresses and their current status.
  • Billing is based on the number of public IP addresses available to your account across all regions.
Networks Usage shown on the Settings page is based on the number of networks currently in use across your environments and templates. A network is “in use” if at least one VM is running on the network.
Max Concurrent VMs The highest number of virtual machines that have been running at one time.

For more information about how usage is calculated against user and department limits, see Setting usage limits.

Types of usage in Skytap, billing, and usage reports


Pay-as-you-go is the default type of usage in Skytap. Pay-as-you-go billing is based on your monthly usage report, which shows actual account usage of the resources listed above.

The billing cycle begins and ends with the calendar month, calculated using UTC.

Administrators can view the account usage report from the Usage page. For more information, see Viewing usage data.

Reserved capacity

If you have Skytap VMs (x86 or Power) that run constantly, you can shift that usage from pay-as-you-go to reserved capacity, which is billed at a reduced rate. Usage beyond your reserved capacity is billed at pay-as-you-go rates.

Reserved capacity billing is based on reserved capacity usage of the resources listed above. Usage that exceeds the reserved capacity is billed at pay-as-you-go rates.

Reserve usage is billed in advance of the reserve period. If you chose automatically renewing reserved capacity, billing for the next reserve period occurs a few days before the end of the current period.

Reserved capacity (RC) usage is calculated as follows:

RC = {resourcee_capacity} × {total_hours_in_reserve_period} × {resource_reserve_rate}

For example

A three-year reserve (2023, 2024, and 2025) of 1024 GB of storage in Skytap on Azure would be calculated as:

1024 × (8,760 + 8,784 + 8,760) × $0.00015 = $4,040.219

2024 is a leap-year.

To reserve capacity, see Reserved capacity for Skytap on Azure or Reserved capacity for Skytap on IBM Cloud.

Controlling Metered RAM and storage usage

For best practices on controlling usage, see Managing Metered RAM and storage usage.

Determining attached license usage for SPLA and IBM i titles

Attached licenses, such as SPLA and IBM i, may result in additional costs beyond standard compute and storage usage. Generally, each instance of an attached license title (operating system or software product) is billed when the host VM is active during the billing period.

If you make a copy of a VM with a attached license title and both the original VM and the copy are active at the same time during the billing period, both VMs are charged for attached license usage.

For details about adding attached licenses to Skytap VMs, see Managing attached licensed titles FAQ.

IBM i Pricing

Additionally, IBM i pricing is dependent on the number of vCPUs. For IBM i VMs, you can choose from the following pricing options:

  • Monthly – IBM i usage is billed at a flat monthly rate – use this model for continuous-use VMs, such as production or automated testing.
  • Hourly – IBM i usage is billed at an hourly rate – user this model for as-needed VMs. The default setting for pricing is Hourly.

If you change the pricing for a VM that has been powered on during the billing cycle, the pricing for that VM won’t be changed until the next billing cycle.