About
Master Key Calculator (MK Calc) is a free, web-based locksmith software platform purpose-built for professional locksmiths who need to create master key systems efficiently. The tool supports all major lock manufacturers — including Schlage, Best, and Lockwood — and handles both Inline and Small Form Interchangeable Core (SFIC) locking hardware. With support for 3 to 7 pin chambers and up to 3 levels of master keying hierarchy, MK Calc gives locksmiths the flexibility to design simple through complex master key systems. Its chamber allocation tools let users customize keying configurations with precision. The platform is fully responsive and accessible from any device — phone, tablet, or desktop — making it practical for on-site work as well as office planning. Completed master key systems can be exported to spreadsheet format, HTML, or directly to MK Express software, streamlining handoff and documentation. Registration is free and unlocks full access to all features. MK Calc is ideal for independent locksmiths, security consultants, and facilities managers who need a fast, reliable way to design and document master key systems without expensive desktop software. The clean, straightforward interface reduces the complexity traditionally associated with master key system planning.
Key Features
- Multi-Brand Support: Compatible with all major lock manufacturers including Schlage, Best, and Lockwood, covering both Inline and Small Form Interchangeable Core (SFIC) hardware.
- 1-3 Level Master Key Systems: Design single, two-level, or three-level master key hierarchies with flexible chamber allocation across 3 to 7 chambers.
- Multi-Device Access: Fully responsive interface that works seamlessly on phones, tablets, and desktops — perfect for both field and office use.
- Export Options: Download your master key system designs as spreadsheets, HTML files, or import directly into MK Express for further processing.
- Free Registration: Completely free to register and use, with no hidden fees or paywalls limiting core master keying functionality.
Use Cases
- A professional locksmith designing a two-level master key system for a commercial office building using Schlage cylinders.
- A security consultant mapping out an SFIC master key hierarchy for a university campus with multiple access zones.
- A facilities manager working with a locksmith to plan and document a grand master key system for a large hotel property.
- A locksmith on-site using their phone to quickly verify or adjust chamber allocations for an inline key system.
- A locksmith exporting a completed master key design to a spreadsheet for client documentation and record-keeping.
Pros
- Completely Free: Full feature access at no cost makes it highly accessible for independent locksmiths and small businesses.
- Cross-Device Compatibility: Works on any device with a browser, enabling locksmiths to plan or review systems on-site without a laptop.
- Broad Hardware Support: Covers most major lock brands and both Inline and SFIC formats, reducing the need for multiple tools.
Cons
- Niche Use Case: Designed exclusively for locksmiths and security professionals; not useful outside of master key system planning.
- Limited Advanced Features: As a free web tool, it may lack the depth of enterprise-level keying software for very large or complex facilities.
Frequently Asked Questions
Is Master Key Calculator really free?
Yes, MK Calc is completely free. Simply register on the site to get full access to all master key system design features at no cost.
Which lock brands does MK Calc support?
MK Calc supports all major brands including Schlage, Best, and Lockwood, and covers both Inline and Small Form Interchangeable Core (SFIC) locking hardware.
How many levels of master keying can I create?
You can create master key systems with 1, 2, or 3 levels of hierarchy, with chamber configurations ranging from 3 to 7 chambers.
Can I export my master key system designs?
Yes. Completed designs can be downloaded as spreadsheets or HTML files, or exported directly into MK Express software.
Does it work on mobile devices?
Yes, MK Calc is fully responsive and works on phones, tablets, and desktop browsers, so you can use it in the field or the office.
