What is the minimum I have to license for one server?

16 cores, even if the server has fewer, and at least 8 per physical processor. The minimum is a floor: if you have more physical cores than that, you license the actual number.

Do I license physical cores or logical (hyper-threaded) cores?

Physical cores only. Hyper-threading and logical processors do not count towards your licence requirement.

How do I count cores on a dual-socket server?

Add the physical cores across both processors. A dual 12-core server is 24 cores, so you license all 24 — after applying the minimums of 8 per processor and 16 per server.

Do unused cores still need licensing?

Yes. You license every physical core in a populated socket, whether the workload uses it or not. You cannot license a subset of a processor's cores.

Do CALs depend on the core count?

No. CALs are separate and per user or device connecting to the server. They must match or exceed your Windows Server version — a 2022 CAL does not cover access to a 2025 server.

Windows Server

How Windows Server core licensing works: the 16-core minimum, core packs and CALs

Windows Server 2022 and 2025 are licensed per physical core. Every server needs at least 16 cores licensed, and at least 8 per processor. Here is how to count what you actually need.

VeriLicense · 6 min read

How is Windows Server licensed?

Windows Server 2022 and 2025 are licensed per physical core. You count the physical cores in the server and license all of them. This applies to both Standard and Datacenter — the edition changes your VM rights, not how cores are counted.

What is the 16-core minimum?

Every server must have at least 16 cores licensed, and at least 8 cores per physical processor — even if the hardware has fewer. A single 6-core processor still needs 16 core licences. A dual-socket server with two 6-core processors also needs 16, because the 8-per-processor minimum applies to each socket.

If your physical core count is above the minimums, you license the actual number. The minimum is a floor, not a cap.

How do I count the cores I need to license?

Count the physical cores across every populated socket. Ignore hyper-threading and logical processors — they do not count. Then apply the minimums:

Fewer than 8 cores in a processor → license 8 for that processor.
Fewer than 16 cores in the server → license 16 for the server.
More than 16 → license the exact physical count.

How do you buy the licences?

You license enough cores to cover every physical core in the server, once the 16-core-per-server and 8-core-per-processor minimums are met. Tell us your processor model and count and we will confirm the exact licences you need.

Worked example

A dual-socket server with two 12-core processors has 24 physical cores. You license all 24. That holds whether you buy Standard or Datacenter, and whether the licence is HPE ROK or volume.

How many VMs does that allow?

With Standard, fully licensing the server’s cores covers 2 VMs; more VMs need additional Standard licensing. With Datacenter, licensing the cores covers unlimited VMs on that server. We cover the edition decision in Standard vs Datacenter.

Do I still need CALs?

Yes. Core licences cover the server software. Every user or device that connects needs a Client Access Licence as well — User or Device, your choice. CALs must match or exceed the server version: a 2022 CAL does not cover access to a 2025 server.

Send us your server model and processor count. We will work out the exact core packs and CALs and quote them the same day.

The bottom line: count every physical core, license at least 16 per server and 8 per processor, then add CALs on top.

Common questions

What is the minimum I have to license for one server?: 16 cores, even if the server has fewer, and at least 8 per physical processor. The minimum is a floor: if you have more physical cores than that, you license the actual number.
Do I license physical cores or logical (hyper-threaded) cores?: Physical cores only. Hyper-threading and logical processors do not count towards your licence requirement.
How do I count cores on a dual-socket server?: Add the physical cores across both processors. A dual 12-core server is 24 cores, so you license all 24 — after applying the minimums of 8 per processor and 16 per server.
Do unused cores still need licensing?: Yes. You license every physical core in a populated socket, whether the workload uses it or not. You cannot license a subset of a processor's cores.
Do CALs depend on the core count?: No. CALs are separate and per user or device connecting to the server. They must match or exceed your Windows Server version — a 2022 CAL does not cover access to a 2025 server.

Next step

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