Directory 👈 Inch or Metric

Common Rafter Calculator - Rafter Dimensions - Plumb Cuts - Birds-mouth Dimensions + Cutting Templates - Inch

Rafter Run Outer Wall
Roof Angle ° : 12
Overhang (level)
Rafter Depth Actual
Rafter Thickness Actual

Wall Thick
Actual Physical Sizes All measurements actual physical sizes
Allow for ridge thickness Allow for Ridge Thickness when determining Rafter Run to Outer Wall.

eg: Half building width minus 1/2 ridge thickness. See Rafter Run to Outer Wall Calculator below.

Print full scale Rafter Cut Templates and Birdsmouth Templates Fold template over rafter to mark or cut through.

Angle Overhang

Rafter calculator angle dimension diagram
scale Use and Keyboard Keys to scale Birds-mouth. Birds-mouth

Rafter calculator dimension diagram

Open page with full scale printable birds-mouth cutting template at current rafter angle and dimensions.

Remember Ridge Thickness Remember to allow for Ridge Thickness in Rafter Run to Outer Wall.

Calculate Rafter Run
to Outer Wall

Building Width
Ridge Thick Actual
Rafter calculator ridge thickness adjustment diagram

DON'T BREATH THE DUST If you're cutting blocks, concrete, stone or ANYTHING and there's DUST - DON'T TAKE THE RISK
Don't cut it, or cut it wet so there's NO DUST - Silicosis Sucks

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