Roof Pitch & Rafter Length Calculator for Australian Framers

Instantly calculate the exact length of your rafters and roof pitch. Perfect for framing estimations in Australia before you contact us for support.

Enter Measurements (mm)

Horizontal distance from the wall plate to the ridge.

Roof Calculation Results

Total Rafter Length

0 mm

Includes overhang

Total Rise

0 mm

Vertical height from wall plate to ridge

Why Use A Roof Pitch Calculator?

When framing a roof, accuracy is critical. A slight miscalculation in pitch or rafter length can lead to wasted materials and structural issues. Our tool uses standard trigonometric functions to give you the exact cut length for your rafters (hypotenuse) and the total rise (opposite) based on your run (adjacent) and pitch angle. Use this tool alongside our timber framing calculator for comprehensive project planning.

Formulas used:

  • Rise = Run × tan(Pitch)
  • Rafter Length (without overhang) = Run / cos(Pitch)
  • Overhang Rafter Length = Overhang / cos(Pitch)