Windows Server: licences by core and CALs explained
Windows Server is licensed by the number of physical cores in the server, with a minimum of 8 cores per processor and 16 cores per server. You also need a client access licence (CAL) for each user or device that connects to it, and a Remote Desktop (RDS) CAL for that service.
The server licence: you count cores
- At least 8 core licences per processor (physical).
- At least 16 core licences per server, even with a single processor or fewer than 16 cores.
- Core licences are sold in packs of 2 and 16. A “16-core” licence therefore covers a server of 16 cores at most.
Standard or Datacenter?
| Standard | Datacenter | |
|---|---|---|
| Virtualised systems included | 2 environments (physical or virtual) | Unlimited |
| More than 2 virtual machines | Possible by relicensing the cores (“stacking”) | Not needed: already unlimited |
| Who it is for | Lightly virtualised server: files, printing, one or two roles | Server hosting many virtual machines |
| Licenciel price | See the product page: 2022 Standard | See the product pages: 2025 Datacenter, 2022 Datacenter |
To choose, first count the virtual machines the server must host.
CALs: one access licence per user or device
Every user or device that accesses a Windows Server server must have a CAL. Choose “user” CALs if your employees connect from several devices, “device” CALs if several people share one workstation.
Remote Desktop (RDS)
To use Remote Desktop Services, an RDS CAL is added to the Windows Server CAL. At Licenciel: RDS 2022, 50 users.
A concrete example
A small company, one server with one 8-core processor, 12 employees, two virtual machines: 16 core licences (the minimum per server), the Standard edition (2 environments), and 12 CALs, plus 12 RDS CALs if employees use Remote Desktop.