Roof Framing Geometry: 2026

RafterTools Updates

RafterTools Books on Geometry, Stereotomy, and Trigonometry.

https://www.raftertools.com/

HG I-II Holy Grail of Roof Framing Geometry & Trigonometry

HG III The Art of the Line for Carpentry Stereotomy Geometry

HG IV Circular Work in Carpentry Stereotomy Geometry

HG V Twisted Circular Work in Carpentry Stereotomy Geometry

HG VI American Trestle Study Pro Stereotomy Geometry

HG VII Building Archimedean Solids and Platonic Solids

RafterTools+ Dark iPhone

RafterTools+ Dark Android

Here's a link to the Raftertools+ Dark website: 14 Roof Framing calculators

https://www.raftertools.com/dark/

A comprehensive suite of roof framing calculators covering equal pitch, irregular hip roofs, polygon roofs, timber framing, bay windows, barrel dormers, eyebrow dormers, round towers, elliptical rafters, groin vaults, and more.

In the evolving world of carpentry, mastering roof framing requires precision, deep knowledge, and the right tools. RafterTools+ Dark is designed to elevate both apprentices and seasoned carpenters by providing a comprehensive suite of calculators and resources that ensure confidence and accuracy in every project.

To truly thrive as a professional carpenter today, you need more than top-notch equipment—you need digital support. The RafterTools+ Dark app complements your toolkit, empowering you to transition from apprentice to journeyman or become the most knowledgeable rough-framing carpenter on any jobsite.

Roof Framing Help Desk iPhone

Here's a link to the Roof Framing Help Desk website

https://www.raftertools.com/bot/

Over 300+ Techniques to choose from.

Expertise in Roof Framing Techniques From Around the World

At Roof Framing Help Desk, we specialize in advanced roof framing techniques. Our expertise includes calculating rafter angles for various roof types, ensuring precision, and a knowledge database of keywords linked to web pages, PDF files, and YouTube videos with roof framing techniques.

The Roof Framing Help Desk app is designed to be a community project similar to Wikipedia. Currently, there are more than 300 keywords to search, 150+ webpages, and over 800 drawings.

Whether it's an irregular Hip Roof, Octagon Roof, Polygon Roof, or a Standard Pitched Roof, the Roof Framing Help Desk app can help you with your roof framing techniques.

Roof Framing Help Desk Android

RPN Carpenters Calc iPhone

Here's a link to the RPN Carpenters Calc website

https://www.raftertools.com/dark/carpenter.html

This Carpenter's Calculator is a Reverse Polish Notation (RPN) calculator, typically an engineering or financial calculator that uses postfix notation. However, this calculator is designed for carpenters and builders, and includes functions specific to construction calculations such as rafter lengths, angles, stair calculations, and more. It also includes standard mathematical functions and basic arithmetic operations. The RPN input method allows quick, efficient calculations without parentheses, making it ideal for on-site use where speed and accuracy are important. Example calculations and instructions for using the various functions of the Carpenter's Calculator are provided below.

I've used the HP 48g & HP 50g calculator since the the 1980's for rafter calculations. So, I designed this calculator to have a similar feel and functionality to those calculators, but with a more modern interface and additional functions specific to carpentry and construction.

Stair Tangent Dark iPhone

Stair Tangent Dark Android

Here's a link to the Stair Tangent Dark website: 12 stair calculators

Calculators cover stringers, risers, circular stairs, elliptical stairs, winders, arch radius, and more.

https://www.stairtangent.com/

Professional Stair Builders don't need an app to build stairs; they just know how. This app is for rough-frame carpenters who don't build stairs every day but could use a stair-building calculator to check their calculations.

Build a set of stairs that you are gonna be proud of. With Stair Tangent Dark, you can eliminate cumulative math errors when building or constructing stairs.

With the Elliptical Stairs calculations and Ellipse Point Layout for X-Y plotting, you can rival any professional stair builder's capabilities.

Crown Tools Dark iPhone

Here's a link to the Crown Tools Dark website: 15 crown molding calculators

https://www.crownmoldingtools.com/

Crown Tools Dark is an app with functions to calculate complex crown miter and bevel angles that other calculators don't offer.

Crown Molding Miter Angle and Saw Blade Bevel Angles

Cathedral ceiling rake crown molding, miter and bevel angles

Vaulted ceiling rake, crown molding, miter, and bevel angles

Rake Crown Molding Miter and Bevel Angles

Polygon Crown Molding Miter and Bevel Angles

Radius BullNose Crown Molding Miter and Bevel Angles and width

Horizontal to Rake Crown Molding Miter and Bevel Angles

Calculate Crown Molding Spring Angles

Calculate Horizontal to Rake Wall No Transitions

Calculate Rake Wall To Horizontal at Corner Wall No Transitions

Calculate Rake Crown to Rake Crown No Transitions

Calculate Rake To Level No Transitions

Calculate Rake To Level Return No Transitions

Calculate Rake To Rake at Peak No Transitions

Calculate Exterior Rake Molding using 3 Different Crown Molding Profiles

Building Solids -- Archimedean and Platonic Solids

Building Solids iPhone

Hollow and Skeletal table saw, and miter saw settings for:

Archimedean Solids

Truncated Tetrahedron

Cuboctahedron

Truncated Cube

Truncated Octahedron

Small Rhombicuboctahedron

Truncated Cuboctahedron

Icosidodecahedron

Snub Cube

Truncated Dodecahedron

Truncated Icosahedron

Rhombicosidodecahedron

Truncated Icosidodecahedron

Snub Dodecahedron

Platonic Solids

Tetrahedron

Cube

Octahedron

Icosahedron

Dodecahedron

CalcX9 iPhone

CalcX9

CalcX9 has 16 built-in calculators for:

Quadratic-> calculates the Quadratic Equation from the three parameters a, b, and c

Parabolic-> calculates and plots the parabolic curve from the three parameters a, b, and c

Law Sines-> calculates the sides and angles of a triangle from the three parameters a, b, and c, or Angle A, Angle B, and Angle C

Law Cosines-> calculates the sides and angles of a triangle from the three parameters a, b, and c, or Angle A, Angle B, and Angle C

Triangle-> calculates the 3 sides and 3 angles of a right triangle, given any two parameters

Ellipse Cone-> calculates and plots the elliptical curve from the given parameters

Hyperbola Cone-> calculates and plots the hyperbolic curve from the given parameters

Parabola Cone-> calculates and plots the parabolic curve from the given parameters

Pyramid-> calculates the pyramid side angles and lengths from the given parameters

Cylinder-> calculates the helical curve and length from the given parameters

Prism-> calculates the volume from the given parameters

Trapezoid-> calculates the volume from the given parameters

Circle-> calculates the helical curve and length from the given parameters

Cone-> calculates the helical curve and length for the cone from the given parameters

Sphere-> calculates the curve and length from the given parameters

Unit Circle-> calculates the cosine, sine, and tan from the given parameters

Snd function button for sin, cos, tan -> for asin, acos, atan functions

Buttons:

x² -> number squared

√2 -> square root of the number

1/X -> 1 / number

+/- -> plus or minus value

π -> prints the number for π

φ -> prints the golden ratio of phi

Included with all apps.

Have some fun with the screen animation. Select your own image to animate or use one of the ten included animation .png files. Like dirt bike, windsurfing, speed boat, sail boat, and some carpenters too

Roof Framing Help Desk app for iPhone

The Roof Framing Help Desk app/Bot is designed to serve as a knowledge base for roof framing techniques and to calculate rafter angles and rafter lengths. It can calculate the rafter angles for equal-pitched, unequal-pitched, and polygon roofs, such as Octagon roofs. It is also a knowledge base for roof framing. Enter a keyword like 'irregular hip roof,' and it will provide you with a link to a web page with explanations on laying out an irregular hip roof. Or enter a keyword like devioement-hip shift, and it will provide you with a link to a webpage for devoiement. Or how to lay out a hip rafter precisely.

There are currently over 300 keywords to search the knowledge database. Over 800 drawings explaining different roof framing techniques, as well as 150 new webpages of information for the keywords in the knowledge database. If you have a webpage, PDF file, or YouTube video you would like to share, you can add it to the knowledge database. The main concept of the knowledge database is to make it similar to Wikipedia, except for roof framing techniques.

Use the built-in rafter length calculator for irregular hip roofs. Include the hip rafter offset calculations for equal overhang.

Download the app on Apple Store
Roof Framing Help Desk app

Roof Framing Help Desk Rafter Length Calculator

Eave Angle: 30-160 degrees, usually 90°
Main Rafter Run: The horizontal distance from the wall plate to the ridge
Main Rafter Pitch: 1-24 roof pitch, or enter the roof slope angle
Adjacent Rafter Pitch: 1-24 roof pitch, or enter the roof slope angle
Hip Rafter Width: The width of the hip rafter: 1-1000
Ridge Width: The width of the ridge
Jack Rafter Width: The width of the jack rafter
Jack Rafter Spacing: Jack Rafter On Center Spacing
Overhang Run: The horizontal distance from the wall plate to the end of the overhang
With the Option to use Hip Rafter Shift: The default is not to use hip rafter shift
With the Option to enter Roof Slope Angles instead of Pitch: 1-89 degrees
With the Option to to display the output in inch or decimal format: The default is to display in inch format
With the Option to calculate the Jack Rafter Length for the first Jack Rafter from the Shortest or Longest Jack Rafter: The default is to calculate from the Shortest

https://www.raftertools.com/bot/rafter-calculator.html