Windows Server License Calculator

Not sure which Windows Server licenses to buy? Enter a few details about your server, and the calculator will compare Standard with Datacenter and estimate the core licenses and CALs you need. It's a guide, not a licensing audit, and it doesn't cover Azure or SPLA licensing.

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Windows Server version

Choose 2025, 2022 or 2019.

202520222019

Number of servers

Enter how many physical servers have this same setup. Processors, cores and virtual machines below are per server.

Physical processors per server

Enter how many physical processors the server has.

Cores per processor

Enter the number of physical cores in each processor.

Number of virtual machines

Enter how many Windows Server virtual machines you plan to run. Enter 0 if none.

Number of users

Enter how many people will access the server.

Number of devices

Enter how many devices will access the server.

User CALs or Device CALs

Choose whether to license each person (User CALs) or each device (Device CALs). You can mix types, but this tool recommends one, so contact us about mixed setups.

Optional Remote Desktop / RDS CALs

If people will use Remote Desktop Services, enter how many users or devices need access. RDS CALs are in addition to Windows Server CALs.

Remote Desktop users

Enter how many people will use Remote Desktop. Enter 0 if none.

Remote Desktop devices

Enter how many devices will use Remote Desktop. Enter 0 if none.

I need Datacenter features (Storage Spaces Direct, software-defined networking, unlimited VMs)

Enter your server details to see your estimate.

How it works

License every physical core: at least 8 per processor and 16 per server.
Standard covers 2 virtual machines each time all of the server's cores are licensed; Datacenter covers unlimited virtual machines.
Every user or device that accesses the server needs a CAL, and RDS CALs are extra.

Core and CAL licensing note: Microsoft's Windows Server 2025 licensing guidance says every physical core needs a license: at least 8 per processor and 16 per server, sold in 2-core packs. Standard covers 2 virtual machines, and every 2 more means licensing all cores again. Datacenter covers unlimited virtual machines. Both need CALs for every user or device, and RDS CALs are extra.