SQL Server Licensing: Per-Core, CAL & Edition Costs

Before you buy SQL Server support or licenses, you need to know which of the two licensing models applies to your deployment, because picking the wrong one is the most expensive mistake in the Microsoft server stack. This page documents the rules and current list prices. All figures are US list prices for SQL Server 2022; volume licensing (EA, CSP, Open Value) transacts below list, and prices carry into SQL Server 2025 with the same structure.

The two licensing models

SQL Server sells under two models. Which one you can use depends on the edition and on who connects to the server.

Per-core. You license every physical (or virtual) core the SQL Server instance can use. No CALs are required — any number of users or devices may connect. Licenses sell in 2-core packs. This is the only model available for Enterprise edition, and it is mandatory when the server is accessed from the internet or by users you cannot count (public web applications, external customers, anonymous traffic). Per-core is also the practical choice above roughly 25–30 internal users, where CAL cost overtakes core cost.

Server + CAL. You buy one server license per operating system environment running SQL Server, plus one Client Access License for each user or device that accesses it, directly or indirectly. Available for Standard edition only. Indirect access counts: if 200 users hit a web app that queries the database through one service account, you need 200 CALs, not one. This rule (multiplexing) is stated in Microsoft's licensing guide and is a standard audit test.

List prices by edition

These are Microsoft list prices. What you actually pay depends on the channel: Enterprise Agreement levels, CSP, and Open Value all discount from list, typically 5–40%. The ratios between editions stay roughly constant, so the model math below holds regardless of channel.

Core minimums

Two floor rules apply under per-core licensing:

• 4-core minimum per physical processor. A single-socket server with a 2-core CPU still requires 4 core licenses (two 2-core packs).
• 4-core minimum per virtual machine. A VM with 2 vCPUs still requires 4 core licenses.

So the entry price for any per-core deployment is two packs: $7,890 for Standard, $30,246 for Enterprise. Hyper-threading does not double the count on physical hardware — you license physical cores, not threads. In a VM, each vCPU counts as one core.

Virtualization licensing

There are two ways to license SQL Server in a virtual environment.

License individual VMs. Count the vCPUs in each VM running SQL Server, apply the 4-core minimum per VM, and buy that many core licenses (or use Server+CAL per VM for Standard). This is the normal approach when a host runs only one or two SQL VMs.

License the host (Enterprise + Software Assurance). License every physical core on the host with Enterprise per-core licenses and keep Software Assurance active on them. This grants the right to run an unlimited number of SQL Server VMs of any edition on that host. Without SA, licensing all host cores with Enterprise permits only one VM per core license. The unlimited-virtualization right exists only with active SA (or its subscription equivalent).

The break-even is mechanical: a 16-core host fully licensed with Enterprise costs $120,984 at list. If you would otherwise license more than roughly 30 Standard vCPUs of separate VMs on that host, host licensing starts to win — and it removes per-VM tracking, which matters when VMs move under vMotion or Live Migration. Moving a licensed VM between hosts more than once per 90 days also requires SA (License Mobility).

What Software Assurance adds

Software Assurance is roughly 25% of the license price per year on top of the license. For SQL Server it is not optional decoration; several rights exist only with SA:

• Failover server rights. One passive instance for high availability, one for disaster recovery, and one passive DR instance in Azure — without buying licenses for them. A passive node must serve no queries and no reports; the moment it does work, it needs its own licenses. Without SA, every failover node needs a full license.
• License Mobility. Reassign licenses between hosts or into authorized third-party clouds more often than the 90-day rule allows.
• Unlimited virtualization on fully licensed Enterprise hosts, as above.
• New version rights. Upgrade to the next release without repurchase.
• Extended Security Update eligibility paths and Azure Hybrid Benefit (below).

Common audit findings

Microsoft and its audit partners (SAM engagements) look for the same items every time. These are the ones that generate the invoices:

• Unlicensed DR and standby servers. A "passive" node without active SA is unlicensed. A passive node that runs backups queried by reports, or serves read traffic, is active and unlicensed even with SA.
• Under-counted cores. The 4-core minimums are missed; vCPU counts changed after deployment; a VM was licensed at 4 cores and later resized to 8.
• Developer edition in production. Developer is feature-identical to Enterprise, so it runs production workloads without complaint. It is never licensed for production. This finding is priced as unlicensed Enterprise cores.
• Multiplexing under Server+CAL. A web or application tier pooling connections does not reduce the CAL count. Every human or device behind it needs a CAL.
• Internet-facing servers on Server+CAL. Uncountable external users make Server+CAL invalid; the deployment should have been per-core from day one.
• VM migration without SA. Clusters with DRS or automatic Live Migration moving SQL VMs between hosts more than once per 90 days, with no License Mobility rights.

Azure Hybrid Benefit

If you own SQL Server licenses with active SA (or license subscriptions), Azure Hybrid Benefit lets you apply them to Azure SQL Database, Azure SQL Managed Instance, or SQL Server on Azure VMs instead of paying the license-included rate. One Enterprise core converts to one vCore at the Business Critical tier or four vCores at General Purpose; one Standard core converts to one General Purpose vCore. During migrations you get 180 days of dual use — the same license may run on-premises and in Azure simultaneously. Details are on Microsoft's Azure Hybrid Benefit page.

Worked examples

Example 1: 20-user line-of-business application

One physical server, single 8-core processor, internal users only, Standard edition fits the workload.

• Server + CAL: $989 + (20 × $230) = $989 + $4,600 = $5,589
• Per-core: 8 cores = four 2-core packs × $3,945 = $15,780

Server+CAL wins at this headcount. The crossover for an 8-core Standard server is about 64 CALs; below that, CALs are cheaper. If the same application were exposed to external customers, per-core would be mandatory regardless of the math.

Example 2: two-node availability group, internet-facing

Two VMs, 8 vCPUs each, Enterprise edition for availability group features, node 2 fully passive. Internet-facing, so per-core is required.

• Active node: 8 cores = four packs × $15,123 = $60,492
• Passive node with SA on the active licenses: $0 in licenses; SA adds roughly 25%/year ≈ $15,123/year
• Passive node without SA: another $60,492

SA pays for itself in year one on any HA pair, which is why failover rights, not upgrades, are the usual reason to carry it.

Reference documents

• SQL Server 2022 pricing — microsoft.com (list prices by edition)
• SQL Server licensing resources — Microsoft Licensing (the licensing datasheet and guide PDFs govern; this page summarizes)
• Editions and features of SQL Server 2022 — Microsoft Learn
• Azure Hybrid Benefit for SQL Server — Microsoft Learn
• Extended Security Updates for SQL Server — Microsoft Learn

Related reading: SQL Server Standard vs Enterprise for the feature differences behind the price gap, and SQL Server versions for support dates by release.

FAQ

How much does SQL Server licensing cost?

At list: Enterprise is $15,123 per 2-core pack (per-core only, 4-core minimum, so $30,246 entry). Standard is $3,945 per 2-core pack, or $989 per server plus $230 per CAL. Volume licensing prices are lower.

Do I need CALs with per-core licensing?

No. Per-core licensing covers unlimited users and devices. CALs only exist in the Standard Server+CAL model.

Is SQL Server Express really free for production?

Yes, within its limits: 10 GB per database, 1 GB of buffer pool memory, and the lesser of one socket or four cores. No CALs, no core licenses.

Does a disaster recovery server need a license?

Not if the primary's licenses carry active Software Assurance and the DR instance is truly passive. Without SA, or if the DR node serves any queries, it needs its own full licenses.