Saltbox Rafter Calculator

Build and check saltbox roof layouts in minutes, right from the jobsite.

Saltbox Roof Calculator is made for roof framers, carpenters, builders, contractors, and serious DIY users who need clear roof framing numbers without manual trigonometry or spreadsheet work.

Enter the building size, front span, roof angles, overhangs, wall height, timber sizes, rafter spacing, birdsmouth seats, and optional battens. The app calculates the measurements you need for planning, cutting, layout, and material takeoff.

Key features:

• Metric and inch input modes
• Equal or exact rafter spacing
• Ridge, front rafter, and rear rafter material lengths
• Roof area, wall height, pitch, soffit drop, and spacing results
• Running ridge and wall measurements for mark-out work
• Optional batten layout and linear length
• Native diagrams for plan, profile, front rafter, and rear rafter
• Export a complete PDF with inputs, results, and diagrams
• Copy summaries, material lists, and running measurements
• Works offline with professional jobsite-friendly defaults

Use it when you need a focused saltbox roof tool instead of a generic construction calculator. Get the numbers, review the diagrams, export the PDF, and keep the crew working from the same clear measurements.