Rafter Tools is an android app with functions to calculate complex roof framing angles that other roof framing calculators don't offer.
Calculating common rafters with a construction calculator is fairly easy, but to be a master carpenter you need more roof framing angle information then the construction calculators offers.
With the Rafter Tools android app you'll be able to calculate all of the complex angles for roof framing. As an American Carpenter & Builder I've written this roof framing calculator
as a roof framing geometry and trigonometry learning tool as well as a roof framing rafter calculator that can be used to build simple gable roofs to the most complex unequal pitched roofs with roof eave angles greater than 90°.
The Rafter Tools app has Quad Tetrahedra Analytic Algorithm Technology to help prevent unconstructable user input.
The Rafter Tools app has support for any roof eave angle from 30° to 180° as well as irregular hip roofs.
All of the roof framing functions are case studies from my book "Holy Grail of Roof Framing Geometry & Trigonometry" .
The app's main screen uses a left swipe motion to display all of the different calculators.
Calculations in Metric or Imperial Units or Base 10
Imperial/English uses the American standard rise over 12"
Metric Millimeters uses the rise in mm over 300mm
Decimal Inch base 10 uses the rise in decimal fractions over 10
User Input Menu Mode
 Imperial/English Inch base 12 —— default.. uses American standard pitches over 12.
 Metric 300mm base —— 300mm is 11.81102 inches, similar usage to the American framing squares printed in inches.
 Decimal Inch base 10 —— use this option when working with tangents or using the Chappell Master Framing Square
multiply the tangent of the angle by 10
 Degrees
The output mode selection can be completely different from the input mode
Output Menu Mode
 Imperial/English Inch base 12 —— default.. uses American standard pitches over 12.
 Metric 300mm base —— 300mm is 11.81102 inches, similar usage to the American framing squares.
 Decimal Inch base 10 —— use this option when working with tangents or using the Chappell Master Framing Square
No Metric to Inches Conversions are required. Enter the pitch in inches and see the results in Metric. French Compagnon charpentiers can work right along side of American carpenters or Australian and British chippys without worring about coverting between Metric, Imperial or Base 10.
Current version 2.62 functions supported:
 Frieze Block Angles
 Frieze Block Miter Angles
 Frieze Block Saw Blade Bevel Angles
 Hip Rafter Roof Angles
 Framing Square Usage for Imperial/English/Metric/Base 10
 Purlin Rafter Angles
 Purlin Rafter Miter Angles
 Purlin Rafter Saw Blade Bevel Angles
 Purlin Rafter Lip Cut Angles
 Hip Rafter Roof Angles
 Framing Square Usage for Imperial/English/Metric/Base 10
 Square Tail Fascia Angles
 Square Tail Fascia Miter Angles
 Square Tail Fascia Saw Blade Bevel Angles
 Square Tail Fascia Hip Rafter Miter Angles
 Square Tail Fascia Hip Rafter Saw Blade Bevel Angles
 Hip Rafter Roof Angles
 Framing Square Usage for Imperial/English/Metric/Base 10
 Bay Window Roof Rafters
 Hexagon Rafter Angles & Lengths
 Octagon Rafter Angles & Lengths
 Dodecagon Rafter Angles & Lengths
 Polygon Rafter Angles & Lengths
Use any part of the polyon as input to find the rest of the angles.
 Common Rafter Run
 Side Wall Length
 Half of Side Wall Length
 Radius
 Hip Rafter Run
 Hip Rafter Length
 Common Rafter Length
 Circumscribed to Radius
 Inscribed to Radius
 Common Rafter Rise
 Timber Framing Angles
 Hawkindale Angles
Use SS or S with DD or D to find the rest of the angles Timber Framing Angles or Hawkindale Angles.
 Hip/ Valley Rafter Roof Angles for equal and unequal roof pitches for any plan angle
 Hip Rafter Backing Angles
 Hip Rafter Plumb Backing Angle
 Hip Rafter Side Cut Angles
 Jack Rafter Side Cut Angles
 Roof Sheathing Angles
 Hip Rafter Purlin Housing Angles
 Hip Rafter Diamond Post Miter & Saw Blade Bevel Angles
 Plywood Roof Sheathing Offset Cut Line
 Valley Sleeper Miter & Saw Blade Bevel Angles
 Dormer Square Tail Miter & Saw Blade Bevel Angles
 Purlin Rafter Miter & Saw Blade Bevel Angles
 Purlin Layover cut perpendicular to roof surface plane
 Purlin Layover cut in the plane of the roof surface
 Irregular Hip roof Rafters
 Irregular Hip roof Rafters With Equal Overhang
 Rake walls.
 Hip Rake walls rotated into roof surface plane.
 Carpentry Certification in roof framing Trigonometry and Geometry.
 Tetrahedron Angles Calculator and Tetrahedron Framing Square Usage
 Dihedral Angles
 French Compagnon Roof Framing Kernel Angles and Framing Square Usage to geometrically draw out a bastard hip using a framing square.
 Crown Molding Miter and Bevel Angles Calculator for Compound Miter Saw Settings
and 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 .
 Hopper Angles
 Jack Rafter Plumb Layout Marks on Hip Rafter
 Unequal Pitched Gable Rafters with Unequal Plate Heights
You can use it as a simple equal pitched gable rafter calculator or use it to calculate unequal pitched gable roofs with unequal plate heights.
 Equal Overhang Rafter Lengths
 First Jack Rafter Length To Long point of miter cut.
 Jack Rafter Length Difference @ jack rafter spacing
 Hip Rafter Backing Offset Main Perpendicular to hip rafter run line.
 Segmental Arches
 Gothic Arches
 Lofting  Plotting Ellipses for Arches or Groin Vaults
 Groin Vault Plotting  Lofting Equal Height Ordinates for Elliptical Cross Vault
Types of Groin Vaults Supported
 SemiCircular Square Groin Vault
 SemiCircular Rectangular Groin Vault
 Segmental Square Groin Vault
 Segmental Rectangular Groin Vault
 Gothic Square Groin Vault
 Gothic Rectangular Groin Vault
 SemiCircular Hexagon Groin Vault
 Segmental Hexagon Groin Vault
 Gothic Hexagon Groin Vault
 SemiCircular Octagon Groin Vault
 Segmental Octagon Groin Vault
 Gothic Octagon Groin Vault
 SemiCircular Dodecagon Groin Vault
 Segmental Dodecagon Groin Vault
 Gothic Dodecagon Groin Vault
 SemiCircular Hexadecagon Groin Vault
 Segmental Hexadecagon Groin Vault
 Gothic Hexadecagon Groin Vault

Alhambra Granada Ad Quadratum Ground Plan Roof Rafters
Clipped Hip Rafter Octagon Roof Framing
Prow Rafter Roof Framing Angles
Octagon Roof Framing 4 Butt Hip Rafter Method
Octagon Roof Framing 4 Butt Hip Rafter Method with Purlin Structural Ring
Octagon Roof Framing With Hip Rafters Mitered
Octagon Roof Framing with Gazebo Cupola
Law of Sines Formulas Reference Sheet
Rectangular Pyramid Hip Roof Geometric & Trigonometric Roof Framing Development for Bastard Hip Roofs
CutIn Dormer Shed Roof Rafter Calculator
Pitch Break Shed Roof Rafter Calculator
Dormer Shed Roof Rafter Calculator
devers de pas for Skewed Rafters rotated into the roof surface plane
Circular Stairs
Spiral  Helical Stairs
Tangent Hand Railing
Trapezoid With Unequal Overhang
Trapezoid With Equal Overhang
Platonic Solids
Archimedean Solids
Rafter Tools App current version 2.62
Functions that will be added soon:
 Radius Rafter Tails  Ski Slope Rafters
 Curved Elongated Hexagon Roof Framing
 Curved Elongated Octagon Roof Framing
Rafter Bevel Angles App current version 1.06
 Jack Rafter Plumb To Earth Bevel Angles.
 Jack Rafter Plumb To Earth Offset Bevel Angles.
 Jack Rafter Plumb To Roof Surface Offset Bevel Angles.
 Rafter Plumb To Earth Offset Bevel Angles.
 Crossing Jack Rafters Plumb To Roof Surface Bevel Angles.
 Saint Andre Cross Rafters Plumb To Roof Surface Bevel Angles.
 Purlin Rafter Plumb To Roof Surface Bevel Angles
 Witches Cut on Hip Rafter with Square Tail Rafters Berechnung der Hexenschnittschmiegen,
 Hip Rafter Edge Bevel Angles, Backing Angles, Dihedral Angle
 Devers De Pas for Jack Rafters Plumb To Roof Surface
 tréteau à dévers... Trestles with tilt... Hip Rafters Rotated into the Roof Surface Plane.
 Claw Lines for the Draw Down Layout Technique
All bevel angles are referenced from the traditional layout method used by the French and Germans carpenters.
This app is for the WorldSkills Carpentry Competition training. With this app the carpenter can verify their geometric layout method while using the traditional layout geometry. It has seat lip cut angles at the hip rafter for all of different types of rotated rafters as well as Hexenschnitt Gratsparren.
Use with the French Rabattement de Surface method (folding) or the German Flachenklappung method.Basiswissen Schiften or Charpente Les Traces.