The correct length rafters are critical to any roofing project. Using our simple calculator is an easy way to get accurate mesurements for your truss dimensions every time.
Rafter Calculator
How to Use
- Measure the Roof Run: the horizontal distance from the wall to the peak of the roof (half the roof span).
- Input Type: Choose whether you will be providing the roof pitch in degrees or the rise of the roof in metres. The "Roof Pitch" is the angle of the roof's slope, while the "Roof Rise" is the vertical height from the base to the peak of the roof.
- Enter Roof Pitch or Rise: input either the pitch of the roof in degrees or the rise of the roof.
- Overhang (optional): If your roof design includes an overhang beyond the wall, enter this measurement.
- Calculate Rafter Length: Click the "Calculate" button to compute the total length of a rafter needed.
Note: This calculator assumes a simple gable roof for the purpose of these calculations.
Calculator checked on By Jamie
Uses
- Home Construction / Renovation: determine the correct rafter lengths for new constructions or renovations ensuring structural integrity and design accuracy.
- Professional Roofing: improve efficiency in planning and reducing material waste by cutting rafters to precise lengths.
- Shed, Garage, and Outbuildings: accurately calculate rafter lengths needed for all roofs.
- Landscaping: For projects that include pergolas, gazebos, or other structures with pitched roofs.
- Historical Restoration: Restoration specialists working on historic buildings can use the calculator to plan the repair or replacement of rafters in keeping with the original roof dimensions and pitches.
More Measurement Calculators
Batten Spacing
Rafter Length
Rainwater Collection
Roof Slope
Roof Tarp Size
Truss Count