Pay Comparison Methodology: What the Scenario Engine Includes
Last reviewed:
Primary tax-year context: Current Australian tax settings
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General information only. This is not tax or financial advice. Consult a registered tax agent for advice specific to your situation.
What the Pay app includes, and where the boundary still matters
The compare engine is designed for responsible planning, not false precision. It reuses the underlying Australian tax logic already used across Austax.tools, then wraps that logic in scenario comparison.
Employee scenarios include
Income tax, Medicare levy, MLS, HELP repayments, salary sacrifice, deductions, residency settings, and pay frequency normalisation.
Bonus scenarios include
The engine estimates the annual tax impact of the bonus and compares it to likely withholding on the bonus pay run.
Contractor scenarios include
Daily, hourly, or annual contract value assumptions, GST registration, business expenses, voluntary super, and employee-equivalent comparison.
What this app does not cover
Payroll tax, payroll admin, employer compliance, entity structuring, or personal advice about your exact legal obligations.
How to use it
Keep the baseline simple, then change one material assumption at a time.
Baseline first
Start with the cleanest credible version of your pay setup. This gives you the benchmark that the alternate scenario will be judged against.
One alternate, not ten
The app is strongest when each alternate scenario answers one decision question clearly, such as “what if I keep the HELP debt?” or “what if I contract at this daily rate?”.
Use the single calculators when you need a narrower answer
For a one-off bonus explanation or a standalone HELP estimate, the root calculators remain the better first tool. Browse the single calculators for focused tools.
Guides and comparisons that use this methodology
- Contractor vs Employee — What actually changes your pay when you switch from PAYG to ABN — GST, super, deductions, and hidden costs.
- Salary Sacrifice — How concessional contributions affect your take-home, HELP repayments, and Medicare levy surcharge.
- HELP Repayment — The 2025-26 marginal repayment system — thresholds, rates, and monthly impact.
Browse all side-by-side comparisons on the compare hub.