What the calculator does
For the year you enter, it computes:
- Net property loss = annual interest minus annual rent. (Ignores depreciation and operating expenses for clarity - the full report includes them.)
- Current-law tax saving = the difference between tax on your taxable income and tax on (taxable income minus the property loss), at 2027-28 Stage 3 tax brackets.
- Reform tax saving = zero. Under the proposed negative-gearing restriction on established residential property from 1 July 2027, the loss is quarantined - it carries forward against future residential rental income only.
What it doesn't do
- Operating expenses, depreciation, land tax all add to the deductible loss. The 3-input calculator ignores them; the full Byrz report includes them per year.
- The carry-forward value. The quarantined loss isn't worthless - it can offset future residential rental income from any property. The calculator treats it as zero because the present value depends on future rental positions that vary widely.
- The interaction with other reforms. The CGT split at 1 July 2027 and the 30% minimum tax floor both affect the same property; the calculator is single-axis.
- Structures other than personal ownership. Trust and SMSF losses are already carried forward inside those structures; the salary-offset advantage was never there. The calculator assumes personal or joint personal ownership.
Caveats
The 2027 negative-gearing restriction is proposed as of late 2026 - not law. See the full explainer: How the proposed 2027 negative gearing restriction works.
For the full multi-year picture on your specific property - cashflow drag, after-tax equity, alternative structures and the carry-forward modelling - see the $49 Byrz property report.