Calculate roof pitch, rafter length and key roof dimensions on the spot. TradeSet’s roof calculator works offline so you’re ready even when reception isn’t.
This calculator is one tool inside the TradeSet app Toolbox: 18 calculators, jobs, history, and PDF export in one place.
Last updated: 18 February 2026
Metric units (mm/m) are used throughout, with Australian standards context where applicable.
Fast on-page input check using metric units for planning only.
Pitch is 21.8 deg with an estimated rafter length of 3.23 m.
General guidance only. Verify with plans/engineer/local requirements.
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Sheet count and lengths for aluminium roofing. For roofers and cladders.
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Open toolRoof pitch and rafter calculations are used every day by roofers and carpenters for quoting, set-out, and ordering. The fastest way to avoid sheet and framing errors is to confirm inputs first, then calculate from one consistent reference point.
On Australian jobs, pitch numbers often need to be checked against manufacturer installation guidance and project documentation before final procurement. This page is written as practical planning support, not compliance sign-off.
Pitch is about 21.8°, and common rafter length (before allowances) is around 3.23 m.
Rafter length is the hypotenuse of the triangle: half-span (run) and rise give you pitch; rafter = √(rise² + run²) in consistent units. Enter rise and half-span in metres in the calculator and it returns pitch in degrees and rafter length. Always use the same reference points on site.
Enter rise and run, and the calculator converts the ratio to degrees. This is useful for communicating set-out and checking manufacturer constraints.
Use the result as a planning baseline, then confirm effective cover, laps, and profile-specific rules from supplier documentation.
The most common issue is input mismatch: measuring from different reference points or using assumed rather than measured dimensions.
Use these links to move from guide to calculator, then continue in the TradeSet app workflow.
Aluminium Roofing Sheets Calculator
Sheet count and lengths for aluminium roofing. For roofers and cladders.
Open calculatorPythagoras Calculator
Right-angle and diagonal lengths for setting out. Quick and accurate for tradies.
Open calculatorCheck Square Calculator
Check and set 90° with diagonal measurements. For setting out and squaring.
Open calculatorStandard Roof Pitch in Australia: Practical Guide for Builders and Roofers
A practical Australian reference for common roof pitch ranges, what they mean on site, and how to avoid ordering or set-out mistakes.
Read guideRafter Length and Roof Pitch Explained: Practical Australian Set-Out Guide
A practical roof framing guide for converting rise/run into pitch and rafter length while avoiding common set-out and ordering errors.
Read guideResults use metric units and should be checked against project drawings and manufacturer guidance. References to Australian standards are general guidance only.
General guidance only. Verify with plans/engineer/local requirements.