SQL Server Licensing Explained: Per Core vs Server + CAL
Updated by the Software Recycling support team
SQL Server is licensed either per core or as Server + CAL. Per core covers unlimited users but needs every physical core licensed, with a minimum of 4 per processor. Server + CAL, available for Standard edition, needs one server license plus a CAL for each user or device. A 15 user pack covers one server and 15 users.
SQL Server is licensed in one of two ways. Per core licensing covers unlimited users and requires every physical core to be licensed, with a minimum of 4 core licenses per processor. Server + CAL licensing, available for Standard edition, needs one server license for each SQL Server installation plus a Client Access License (CAL) for each user or device. Enterprise edition is licensed per core.
Per core vs Server + CAL
Choose Server + CAL when you can count your users and the number is small. Choose per core when there are many users, or you cannot count them.
| Server + CAL | Per core | |
|---|---|---|
| Editions | Standard | Standard and Enterprise |
| What you license | Each server, plus each user or device | Every physical core |
| User limit | One CAL per user or device | Unlimited users |
| Minimum | One server license | 4 core licenses per processor |
| Good for | Internal databases with a known team | Customer-facing apps, large or unknown user counts |
How Server + CAL works
Each server running SQL Server needs a server license, and each user or device that accesses SQL Server needs a SQL Server CAL. The CAL version must be the same as or newer than the server version.
CALs count everyone who uses the data, not just people who log in to SQL Server directly. Microsoft's multiplexing rule means users who reach the database through an application, a web site or a shared service account still need a CAL each.
How per core licensing works
Per core licensing covers the server's processing power instead of its users.
- Count every physical core on every processor.
- Apply the minimum of 4 core licenses per processor.
- Buy core licenses, typically in 2-core packs, to match the total.
Per core licensing also covers external users without counting them, which makes it the practical choice for public web applications.
What does a "15 user" Server + CAL pack mean?
A 15 user pack is a Server + CAL bundle for SQL Server Standard. It includes the server license for one SQL Server installation and CALs for 15 users. That suits a small business where up to 15 named people use the database through accounting, CRM or line of business software.
If you grow beyond 15 users, you need more CALs or a move to per core licensing. Our SQL Server Standard packs include SQL Server 2022 Standard, SQL Server 2025 Standard and SQL Server 2019 Standard.
SQL Server Standard vs Enterprise
Standard is enough for most small and medium businesses. Enterprise is for workloads that need more processor power, more memory, or advanced high availability.
| Standard 2022 | Standard 2025 | Enterprise | |
|---|---|---|---|
| Max compute per instance | Lesser of 4 sockets or 24 cores | Lesser of 4 sockets or 32 cores | Operating system maximum |
| Max buffer pool memory per instance | 128 GB | 256 GB | Operating system maximum |
| Always On availability groups | Basic (2 replicas, 1 database) | Basic (2 replicas, 1 database) | Full |
| Licensing models | Server + CAL or per core | Server + CAL or per core | Per core |
Standard's limits apply per instance, not per server. A SQL Server Standard instance on a 48-core server still uses only its edition's maximum.
If your database needs more than Standard's limits, look at SQL Server 2022 Enterprise, which is offered as a 64-core license.
SQL Server licensing in virtual machines
Virtual machines are where SQL Server licensing gets complicated, so check the rules for your version before planning a virtual deployment.
- Licensing the physical host. License all physical cores of the host. With SQL Server Enterprise and all cores licensed, customers with Software Assurance or subscription licenses get unlimited virtualization.
- Licensing individual virtual machines. Each VM is licensed by its virtual cores, with a minimum of 4 core licenses per VM.
- SQL Server 2022 and later. Microsoft's licensing terms make licensing by individual virtual machine, and unlimited virtualization with Enterprise, benefits of Software Assurance or subscription licenses. A perpetual license on its own does not include them.
A straightforward option for a perpetual license is a physical server, or a host dedicated to SQL Server where all physical cores are licensed. If you plan to run SQL Server in a virtual machine, contact support with your setup before buying.
Downloading SQL Server 2022 and 2025
Microsoft distributes SQL Server through the Microsoft Evaluation Center as a 180-day evaluation. You install the evaluation, then convert it with your product key.
- Download the SQL Server evaluation for your version from the Evaluation Center.
- Run setup and install the Database Engine and the features you need.
- Open SQL Server Installation Center from the Start menu.
- Select Maintenance, then Edition Upgrade.
- Enter your product key and complete the wizard.
- Restart the SQL Server service if prompted.
Microsoft also offers free editions. Developer editions are licensed for development and testing only, not production. Express is free for production but limited to the lesser of 1 socket or 4 cores and a small maximum database size.
SQL Server also needs Windows Server licenses
SQL Server runs on Windows Server, which is licensed separately by physical core, and users of that server need Windows Server CALs. See Windows Server core licensing explained and our guide to installing Windows Server.
Need help?
If you are deciding between a 15 user pack and per core licensing, or between Standard and Enterprise, open a ticket at /support or call +1-888-470-5516. Free tech support is available 7 days a week, and if a key fails to activate we send a working replacement free of charge.
