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
1. Imperial/English Inch base 12 —— default.. uses American standard pitches over 12.
2. Metric 300mm base —— 300mm is 11.81102 inches, similar usage to the American framing squares printed in inches.
3. 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
4. Degrees

The output mode selection can be completely different from the input mode

Output Menu Mode
1. Imperial/English Inch base 12 —— default.. uses American standard pitches over 12.
2. Metric 300mm base —— 300mm is 11.81102 inches, similar usage to the American framing squares.
3. 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:

1. 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
2. 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
3. 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
4. Bay Window Roof Rafters
   
5. Hexagon Rafter Angles & Lengths
6. Octagon Rafter Angles & Lengths
7. Dodecagon Rafter Angles & Lengths
8. 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


9. Timber Framing Angles
   
10. Hawkindale Angles
    Use SS or S with DD or D to find the rest of the angles Timber Framing Angles or Hawkindale Angles.
    
11. 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
12. Irregular Hip roof Rafters
    
13. Irregular Hip roof Rafters With Equal Overhang
    
    
14. Rake walls.
    
15. Hip Rake walls rotated into roof surface plane.
    
    
16. Carpentry Certification in roof framing Trigonometry and Geometry.
17. Tetrahedron Angles Calculator and Tetrahedron Framing Square Usage
    
18. Dihedral Angles
19. French Compagnon Roof Framing Kernel Angles and Framing Square Usage to geometrically draw out a bastard hip using a framing square.
20. 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 .
21. Hopper Angles
22. Jack Rafter Plumb Layout Marks on Hip Rafter
23. 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
  1. Semi-Circular Square Groin Vault
  2. Semi-Circular Rectangular Groin Vault
  3. Segmental Square Groin Vault
  4. Segmental Rectangular Groin Vault
  5. Gothic Square Groin Vault
  6. Gothic Rectangular Groin Vault
  7. Semi-Circular Hexagon Groin Vault
  8. Segmental Hexagon Groin Vault
  9. Gothic Hexagon Groin Vault
  10. Semi-Circular Octagon Groin Vault
  11. Segmental Octagon Groin Vault
  12. Gothic Octagon Groin Vault
  13. Semi-Circular Dodecagon Groin Vault
  14. Segmental Dodecagon Groin Vault
  15. Gothic Dodecagon Groin Vault
  16. Semi-Circular Hexadecagon Groin Vault
  17. Segmental Hexadecagon Groin Vault
  18. Gothic Hexadecagon Groin Vault
  19.