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Stairs
mm
mm
Australian Stair Calculation Formula
Ideal Rise Height = 175mm (Australian standard)
Number of Rises = Total Rise ÷ Ideal Rise Height (rounded up)
Unit Rise = Total Rise ÷ Number of Rises
Number of Treads = Number of Rises - 1
Total Run = Number of Treads × Tread Run
Stringer Length = √(Total Rise² + Total Run²)
2R + G = (2 × Unit Rise) + Tread Run
Australian Compliance = 2R + G between 550mm and 700mm
Number of Rises = Total Rise ÷ Ideal Rise Height (rounded up)
Unit Rise = Total Rise ÷ Number of Rises
Number of Treads = Number of Rises - 1
Total Run = Number of Treads × Tread Run
Stringer Length = √(Total Rise² + Total Run²)
2R + G = (2 × Unit Rise) + Tread Run
Australian Compliance = 2R + G between 550mm and 700mm
Australian Standards:
• Riser Height: 115mm to 190mm (175mm ideal)
• Tread Depth (Going): Minimum 240mm
• 2R + G Formula: Must be between 550mm and 700mm
• Refer to National Construction Code (NCC) for specific requirements