Gambrel Roof Truss Calculator – Calculate Your Roof Dimensions Easily

Use this gambrel roof truss calculator to easily determine the key dimensions and materials needed for your roofing project.

How to Use the Calculator:
To calculate the rafter length for a gambrel roof, follow these steps:

  1. Enter the ridge length in feet.
  2. Enter the roof pitch as x/12 (for example, 4/12).
  3. Enter the length of the overhang in feet.
  4. Enter the height of the eave in feet.
  5. Click the “Calculate” button.
  6. Review the result provided in the “Result” field.

How the Calculator Works:
This calculator uses the following formula to determine the total rafter length for a gambrel roof:
Total Rafter Length = sqrt((Ridge Length/2)2 + (Pitch)2) + Eave Height + Overhang

This calculator assumes symmetrical gable roof shapes and does not take into account unique architectural features or non-standard designs. Measurements should always be double-checked by a professional to account for factors such as load requirements, lumber size variations, and local building codes.

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