Client Access License (CAL) Calculator
Tell it which on-premises servers your people reach — Windows Server, Exchange, SharePoint, SQL Server, Remote Desktop Services, Configuration Manager — and which Microsoft 365, Office 365 or EMS seats you already own. It answers per product: User or Device CALs, how many are still to buy once CAL equivalency is counted, the RDS and SQL CALs no cloud plan covers, and whether an External Connector beats per-user CALs for outside users — with Microsoft list prices wherever the price list carries the part.
01 On-premises products in use
Pick everything your people connect to. Each one gets its own user and device counts.
02 Cloud seats you already own
Seats per plan. A seat stands in for the CALs listed under it — for that same user, across every product at once.
03 Price basis
Windows Server on its own already answers the most common question: how many CALs are left to buy once Microsoft 365 seats are counted.
Three inputs, and three scenarios to try.
Quick start
- Pick the products in use and enter the users and devices that reach each one — devices matter when people share PCs.
- Enter the cloud seats you own per plan; each seat is subtracted from the CALs it stands in for, for that same user.
- Add external users where customers or partners reach a server, and the External Connector alternative appears.
- Read the per-product cards, then open the result as a quote page or copy the summary.
Tip: RDS and SQL Server CALs are never reduced by cloud seats — if those are your big numbers, the seats you own change nothing there.
Example scenarios
01Shift-work plant
Windows Server 2025 and RDS, 300 users on 120 shared PCs, 300 Microsoft 365 F3 seats. Device CALs win for RDS; the F3 seats cover the Windows Server CALs.
Load this scenario →Hybrid office on E3
Windows Server, Exchange SE and SharePoint SE for 150 users with 150 Microsoft 365 E3 seats. Nothing left to buy except the 40 RDS CALs for the admins' jump hosts.
Load this scenario →Customer portal
Windows Server 2025 with 60 employees and 2,000 external users across 2 servers. Two External Connectors against 2,000 User CALs — the calculator shows both.
Load this scenario →How CALs work in 2026
A server license lets the software run; a Client Access License lets someone use it. Windows Server, Exchange Server, SharePoint Server, SQL Server Standard in Server + CAL mode, Remote Desktop Services and Configuration Manager each need a CAL (or, for Configuration Manager, a client management license) for every user or device that accesses them, directly or through another application. Public-facing workloads where nobody can count the users license the server another way — per core for SQL Server, an External Connector for Windows Server.
User CAL or Device CAL is a per-product choice, and the two can be mixed. A User CAL follows the person across every device they use; a Device CAL follows the desk, whoever sits at it. Two shifts on 120 shared PCs is 120 Device CALs, not 300 User CALs; a sales team with a laptop, a phone and a tablet each is one User CAL per person. The calculator recommends whichever kind leaves fewer CALs to buy and shows both numbers.
Cloud seats stand in for CALs — for the same user, not the whole estate. Microsoft’s Product Terms list “CAL Equivalency Licenses”: a Microsoft 365 E3 or E5 seat covers that user’s Windows Server, Exchange, SharePoint and Configuration Manager licenses at once; Office 365 E-plans cover Exchange and SharePoint but not Windows Server; EMS covers Windows Server and Configuration Manager; the frontline F-plans cover a narrower set; the Business plans are modelled with none. Seats never cover a second user, never cover a device, and never cover RDS or SQL Server CALs.
Versions still matter. A CAL must be the same version as, or newer than, the server it accesses; a newer CAL reaches an older server through downgrade rights. The current price list sells the 2025 generation of Windows Server, RDS and SQL Server CALs and the 2019 generation of Exchange and SharePoint CALs, alongside the version-less Open Value CALs with Software Assurance that the Subscription Editions require.
The Subscription Editions changed the shape of the purchase. Exchange Server SE and SharePoint Server SE need an active subscription license or Software Assurance on the server licenses and the CALs — or CAL equivalency from a qualifying cloud seat. Exchange Server 2016 and 2019 left support on 14 October 2025, so for most organizations the honest comparison is no longer 2019 versus SE but SE versus the cloud service. Our licensing and true-up advisory turns the calculator’s counts into a position you can sign.
Assumptions and sources
Every rule the engine applies, with its source and verification status. “Verified” means a reachable Microsoft Learn page states it (date shown); “pending” means the statement is modelled from the Product Terms and has not yet been checked against the current Terms. Rule IDs match the notes in the results.
- EQ-M365-EA Microsoft 365 E3 or E5 seat stands in for that user's Windows Server CAL, Exchange Server Standard and Enterprise CALs, SharePoint Server Standard and Enterprise CALs, and Configuration Manager client management license. (Skype for Business Server CALs are included too and ignored here.)Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-M365-F3A Microsoft 365 F3 seat is modelled as standing in for the Windows Server CAL, Exchange Server Standard CAL, SharePoint Server Standard CAL and Configuration Manager client management license — Standard CALs only. Enterprise CAL equivalency is not assumed for frontline plans; if the Product Terms grant it, the calculator understates coverage, never overstates it.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-M365-F1A Microsoft 365 F1 seat is modelled as standing in for the Windows Server CAL and Configuration Manager client management license only — no Exchange Server or SharePoint Server CAL.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-O365-E1An Office 365 E1 seat stands in for the Exchange Server Standard CAL and SharePoint Server Standard CAL. It carries no Windows Server CAL.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-O365-E3E5An Office 365 E3 or E5 seat stands in for the Exchange Server Standard and Enterprise CALs and the SharePoint Server Standard and Enterprise CALs. It carries no Windows Server CAL.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-EMSAn Enterprise Mobility + Security E3 or E5 seat stands in for the Windows Server CAL and the Configuration Manager client management license. (The Configuration Manager half is confirmed under CM-EQ; the Windows Server CAL half is pending.)Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-BUSINESSMicrosoft 365 Business Premium, Business Standard and Business Basic are modelled with no CAL equivalency at all. Configuration Manager is confirmed not included in Business Premium (CM-EQ); the Windows Server, Exchange Server and SharePoint Server positions are pending.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- EQ-SAME-USEROne seat covers every CAL in its list for the same user at once — never a second user, and never a device. Cloud seats reduce User CAL counts only, and coverage is capped at the number of users who access each product.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- CM-EQConfiguration Manager current branch requires active Software Assurance or an equivalent subscription. Microsoft lists the Management License Equivalent Licenses as the Intune user subscription, EMS E3, EMS E5, Microsoft 365 E3, Microsoft 365 E5 and Microsoft 365 F3 — and states that Configuration Manager is not included in Microsoft 365 Business Premium.Source: Microsoft Learn — Configuration Manager product and licensing FAQ (ms.date 2024-12-16)VERIFIED 2026-09-13
- CM-SQLThe SQL Server instance that hosts only Configuration Manager databases needs no SQL Server CALs — that use is covered by the Configuration Manager license.Source: Microsoft Learn — Configuration Manager product and licensing FAQ (ms.date 2024-12-16)VERIFIED 2026-09-13
- RDS-REQEach user and each device that connects to a Remote Desktop Services session host needs an RDS CAL, on top of the Windows Server CAL. Per-device RDS CALs suit two or more shifts of workers sharing the same PCs; per-user suits people with their own devices.Source: Microsoft Learn — License Remote Desktop Services with Client Access Licenses (ms.date 2025-06-16)VERIFIED 2026-09-13
- RDS-VERSIONAn RDS CAL must be the same version as, or newer than, the session host it connects to: a Windows Server 2022 RDS CAL reaches a 2022 or older host, never a 2025 host.Source: Microsoft Learn — License Remote Desktop Services with Client Access Licenses (ms.date 2025-06-16)VERIFIED 2026-09-13
- RDS-NOEQNo Microsoft 365, Office 365 or EMS plan carries RDS CAL equivalency — cloud seats never reduce the RDS CAL count.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- SQL-NOEQSQL Server CALs are never covered by a cloud subscription. SQL Server Standard in Server + CAL mode needs a CAL for every user or device that connects, directly or through middleware; past a certain headcount, per-core licensing costs less.Source: Microsoft Product Terms — SQL ServerPENDING VERIFICATION
- CAL-VERSIONA CAL must be the same version as, or newer than, the server it accesses; a newer CAL reaches an older server through downgrade rights. The current price list sells the 2025 generation of Windows Server, RDS and SQL Server CALs, so those are what the calculator prices for older hosts.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- SE-SAExchange Server Subscription Edition and SharePoint Server Subscription Edition require an active subscription license or Software Assurance on the server licenses and on the CALs — or CAL equivalency from a qualifying cloud seat. Perpetual 2019 CALs without Software Assurance do not qualify.Source: Microsoft Product Terms — Exchange Server / SharePoint ServerPENDING VERIFICATION
- EXT-CONNECTORA Windows Server External Connector licenses every external user (a non-employee: customer, partner, supplier) of one server in place of per-user CALs — one connector per server. The current price list carries a Windows Server External Connector but none for Exchange Server or SharePoint Server, so external access to those is priced by a human.Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
- USER-DEVICEUser CALs and Device CALs can be mixed within one organization; the calculator recommends whichever kind leaves fewer CALs to buy after equivalency, and treats a tie as User CALs (they follow the person, not the desk).Source: Microsoft Product Terms — CAL Equivalency LicensesPENDING VERIFICATION
Prices: Windows Server, RDS, SQL Server and Exchange/SharePoint 2019 CALs and the Windows Server External Connector from the current US CSP software price list (see the software catalog); Subscription Edition CALs and the Configuration Manager license from the Open Value price list as budgetary figures (see Volume Licensing). Anything the lists do not carry is shown as a quantity and quoted by a human.
Frequently asked questions
Do I still need Windows Server CALs if every user has Microsoft 365 E3?
Not for those users. A Microsoft 365 E3 or E5 seat stands in for that user's Windows Server CAL (and their Exchange Server, SharePoint Server and Configuration Manager licenses) — one seat, one user, every product at once. You still buy CALs for anyone without a seat, for shared devices you license per device, and for external users. Enter the seat count in section 02 and the calculator subtracts it per product, never below zero.
Does Microsoft 365 Business Premium include CAL equivalency?
The calculator models Business Premium, Business Standard and Business Basic with no CAL equivalency: Microsoft's Configuration Manager licensing FAQ states Configuration Manager is not included in Business Premium, and the Windows Server, Exchange and SharePoint positions are pending verification against the Product Terms. If you rely on Business Premium seats for on-premises CALs today, that is the first thing to confirm with a human.
Can a Windows Server 2025 CAL be used with a Windows Server 2019 host?
Yes. A CAL must be the same version as, or newer than, the server it accesses, and a newer CAL reaches an older server through downgrade rights. The reverse does not work: a 2019 CAL cannot access a 2025 host. The current price list sells the 2025 generation of Windows Server, RDS and SQL Server CALs, so that is what the calculator prices for older hosts and says so on the line.
Are RDS CALs included in any Microsoft 365 plan?
No. Remote Desktop Services CALs are never covered by a cloud subscription, and every RDS user or device needs one on top of the Windows Server CAL. Microsoft's own guidance: per-device RDS CALs for shift workers sharing PCs, per-user for people with their own devices, and the RDS CAL version must be the same as or newer than the session host. The calculator leaves RDS counts untouched by cloud seats and prices them from the current list.
What changes with Exchange Server SE and SharePoint Server SE?
The Subscription Editions require an active subscription license or Software Assurance on the server licenses and on the CALs — or CAL equivalency from a qualifying cloud seat. Perpetual 2019 CALs without Software Assurance do not qualify. Exchange Server 2016 and 2019 left support on 14 October 2025, so the Subscription Edition is the only supported on-premises Exchange; the calculator prices SE CALs from the Open Value list as budgetary L&SA figures and links the family page.
Sizing the servers too? The Windows Server Licensing Calculator does the core math, and the SQL Server Licensing Calculator compares Server + CAL with per-core.
Turn the count into a license position.
Thirty minutes with an engineer and the pending rules above are checked against your agreement, your cloud seats and your servers — fixed price, pay after approval.