ArchMM
Scale & Carpenter Calculator
Free
Three practical calculators. Convert model scales, work in feet and inches, and plan board feet, stairs, and rafters—all in one focused workspace.
Scale, measure, and calculate with ArchMM.
A practical calculator for designers, model makers, builders, architects, and students—built around feet, inches, fractions, and architectural scale.
MODEL SCALE
Convert full-size feet and inches to model millimeters for 3D printing and model making, or work backward from a model measurement. Choose 1:1 or common architectural scales and compare the converted length with a printer-bed preset.
CARPENTER CALCULATOR
Use dedicated number, unit, fraction, and arithmetic buttons. Add and subtract dimensions, multiply lengths into area or volume, recall memory, and revisit recent calculations. The next number after equals starts a new calculation.
SCALE TO INCHES
Enter a full-size measurement and get its scaled size in inches. Change the drawing scale at any time.
PROJECT TOOLS
Calculate board feet, explore a stair layout, and work out common-rafter geometry. Each tool explains its assumptions. These are geometry estimates, not structural design or code-compliance approval.
MADE FOR EVERYDAY WORK
• Copy results for your next task
• Light, Dark, and System appearance
• On-device calculations with no account, ads, analytics, or tracking
• No internet connection needed for calculations
Printer checks compare one converted length with the bed dimensions. Confirm the complete part geometry, orientation, and clearances in your slicer.
Ratings & Reviews
ArchMM now brings three calculators into one focused workspace.
• New Carpenter calculator with feet, inches, fractions, arithmetic, memory, and recent calculations.
• New Scale to Inches mode with changeable architectural scales.
• New Board Feet, Stair Layout, and Common Rafter project tools.
• A more prominent Model scale control for 3D-printing conversions.
• Updated app-family design and icon.
• Updated website, support, and privacy links.
The developer, Brandon Davis, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Brandon Davis
- Size
- 6.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Brandon PT Davis