Work out drain drop and grade from run length and fall %, or from invert levels. Default 1.65% is 1:60, a common AS/NZS 3500.2 grade for DN100. Offline for site set-out.
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Last updated: 30 August 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.
Adjusted planning quantity is 111 units (base 100 with 10% allowance).
General guidance only. Verify with plans/engineer/local requirements.
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Open toolDrain Fall & Grade Calculator is built for Australian tradies who need fast, practical answers while planning work, ordering materials, or checking quantities on site.
It supports metric workflows (mm/m) and helps you move from raw measurements to usable outputs without spreadsheet delay. Use this page as an answer resource first, then as a tool.
Drop is 198 mm (about 1:61). End invert is 1.302 m. 1.65% is a common AS/NZS 3500.2 grade for DN100.
Drain Fall & Grade Calculator gives fast planning outputs for measuring, ordering, and quoting tasks on Australian jobs in metric units.
No. Use outputs as general guidance only, then verify decisions against approved plans, engineering advice, and local requirements.
Yes. TradeSet is designed for on-site workflows where reception can be unreliable, with calculators and saved context available quickly.
Use these links to move from guide to calculator, then continue in the TradeSet app workflow.
Outputs use metric units and are intended as general guidance for Australian site planning. Check NCC/AS and project-specific requirements for your situation.
General guidance only. Verify with plans/engineer/local requirements.