Frequently asked questions

Azure Hybrid Benefit is frequently not cost-effective for burstable B-series VMs. Their hourly Windows charge is low, so buying the 8-core minimum in licences usually costs more than it saves. The calculator lists them but leaves them unticked. Tick one to include it and compare the cost-benefit yourself.

You only pay the pay-as-you-go Windows charge while a VM is running. Licences cost the same whether the VM runs or not. So a VM that is shut down overnight and at weekends saves less by switching to your own licences, and may cost more.

The calculator assumes every VM is always on (730 hours a month), which is typical for production servers. For VMs that are shut down part of the time, change Hours running / month for that VM in the table, or select the VM and pick a preset such as weekdays for 12 hours a day (about 261 hours). The VM's detail panel also shows the minimum hours it needs to run for licences to pay for themselves.

We take your data privacy seriously. Your CSV file is read in your browser and never uploaded. To look up prices, the calculator sends only the VM size of each VM (plus the vCPU count for VMs you add by hand) and your chosen currency to our pricing API. VM names, resource groups, subscriptions and regions are not sent. We do not store your VM data or calculation results on our servers.

Like most websites, this site uses Google Analytics to count visits and Google AdSense to show ads. These services set cookies and receive standard browser information, but not your VM data.

Azure Hybrid Benefit is a licensing benefit that allows you to use your on-premises Windows Server licences with Software Assurance to run Windows Server virtual machines in Azure at a reduced cost.

The calculator uses the following rules:

• Each VM requires a minimum of 8 core licences (4 two-core packs).
• Above 8, every vCPU needs a core licence. Licences are sold in 2-core packs, so an odd vCPU count is rounded up to the next whole pack.
• The total is then calculated across all your VMs.

Azure Hybrid Benefit itself is free. What you pay for is the Windows Server licences (with Software Assurance or a subscription) that entitle you to use it. The licence term sets the period the calculator compares: the price you enter for a 2-core pack should cover that whole term, and it is compared against the pay-as-you-go Windows charge over the same number of months.

A longer term usually shows a bigger saving because the monthly pay-as-you-go charge keeps adding up while the licence cost is fixed. It only works out cheaper overall if your 3-year pack price is less than three times your 1-year price.

No, this calculator only covers Windows Server VMs. Azure Hybrid Benefit does exist for Linux: you can bring Red Hat Enterprise Linux (RHEL) and SUSE Linux Enterprise Server (SLES) subscriptions to Azure. Those savings are not modelled here. (Microsoft documentation on Azure Hybrid Benefit for Linux)

The estimates use Azure retail pay-as-you-go prices for each VM size and the pack price you enter. They are a guide, not a quote. Actual savings may differ because:

• Windows rates can vary by region, and the calculator does not price by region.
• Your agreement may include negotiated discounts on Azure or on licences.
• Azure prices change over time.
• VMs that are shut down for part of the month cost less on pay-as-you-go. Every VM is assumed to be always on unless you change its hours in the table.

The calculator provides a default value, but for the most accurate results, you should use the actual price you pay for your Windows Server licences. Contact your Microsoft representative or licence reseller for precise pricing. For a rough indication, you can search for the SKU "DG7GMGF0D5RK:0007" and use search results.

It depends on the session host operating system. Windows 10 and Windows 11 multi-session hosts are licensed through eligible Microsoft 365 or Windows Enterprise licences, not Windows Server, so Azure Hybrid Benefit for Windows Server does not apply. Session hosts running Windows Server (Remote Desktop Session Host) can use Azure Hybrid Benefit for the Windows Server licence, and you can add those VMs to this calculator.

It's a good practice to recalculate your potential savings periodically, especially after significant changes to your VM infrastructure or when your Windows Server licences are up for renewal.

No, this calculator focuses on the savings from Azure Hybrid Benefit alone. Combining Azure Hybrid Benefit with Reserved Instances could lead to additional savings, but that's not calculated here.