Wind Loads (AS/NZS 1170.2:2011)
Run the calcThis calculator uses an earlier code edition (AS/NZS 1170.2:2011 (Amdt 5)). It stays available for existing projects. For new designs, check the Calculator Library for the current edition.
Method & scope
How to use it
1
Open the calculator
Open it from Run calc in the About this calculator panel above.
2
Enter your inputs
Work through the input sections from top to bottom. Click any input label to see its reference explanation, clause, conditions and assumptions. See Checks, References, Conditions and Assumptions.
3
Review the results and export
Check the utilization of each governing check in the summary, then export a PDF report. See Views and Export.
Common questions
What design standard does this calculator use?
What design standard does this calculator use?
The calculator implements AS/NZS 1170.2:2011 (Amdt 5), Structural design actions: Wind actions. This is the 2011 edition referenced by NCC 2019 and earlier. It covers wind regions A through D, terrain categories TC1 through TC4, and the multiplier-based site wind speed method.
What are the key inputs?
What are the key inputs?
Key inputs are wind region and design return period, terrain category (TC1 through TC4), site topography (hill, escarpment, or flat), shielding parameter, building height and plan dimensions, structure importance level, and cardinal direction weighting. Topographic multiplier (Mt), shielding multiplier (Ms), and directionality multiplier (Md) can each be overridden if site-specific data is available.
What outputs does the calculator return?
What outputs does the calculator return?
Outputs include regional wind speed (VR), site wind speed (Vsit,b) for each wind direction, design wind speed (Vdes,theta), velocity pressure (qz,des), and external and internal pressure coefficients for each building surface zone. Code clause references from AS/NZS 1170.2:2011 are shown alongside every calculated value.
How does this differ from the AS/NZS 1170.2:2021 version?
How does this differ from the AS/NZS 1170.2:2021 version?
The 2021 revision updated wind region boundaries (particularly in coastal Queensland), revised terrain category multiplier tables, introduced the Climate Change Multiplier (Mcm), and aligned definitions more closely with international standards. If your project is under NCC 2019 or requires the 2011 edition, use this calculator. For NCC 2022 projects, use the AS/NZS 1170.2:2021 version.
Can terrain and shielding multipliers be overridden?
Can terrain and shielding multipliers be overridden?
Yes. Terrain/height multiplier (Mz,cat), shielding multiplier (Ms), and topographic multiplier (Mt) can all be set to custom values when site-specific assessment data is available. This is common for complex terrain, dense urban shielding configurations, or when a wind engineer provides site-specific multipliers for a detailed study.
Next steps
Calculator Library
Complete list of Calcs.com design calculators available for Australian and New Zealand projects (AS 3600, AS 4100, AS 1720, AS/NZS 1170, and related standards).