Is this superannuation family law split calculator free?

Yes. The pre & post cohabitation split calculator is free to use and produces an indicative split based on the inputs you provide. For a court-admissible figure, you'll need a signed actuarial report — but the calculator gives you a strong feel for the likely numbers before you spend anything.

How accurate is the family law split calculator?

The calculator uses APRA-published industry returns for the period and a simplified contribution model to separate the pre-cohabitation and post-cohabitation components. It is accurate enough for negotiation framing and to scope a fixed-fee report — but it is explicitly an estimate, not a court-format valuation.

Can I save or download the results?

Yes — you can download a mediation-ready PDF summary with your inputs, the calculated post-cohabitation (matrimonial) pool, the grossed-up pre-cohabitation slice, and a clear methodology disclosure.

Does the calculator handle defined benefit interests?

Not directly. Defined benefit interests require prescribed-method calculations under the Family Law (Superannuation) Regulations 2025, which depend on factors not captured in the pre & post cohabitation split calculator. Use the calculator for accumulation interests; book a report for DB interests.

What inputs do I need for the pre & post cohabitation split calculator?

Cohabitation date, separation date, pre-cohabitation super balance for each party, post-cohabitation (separation-date) super balance for each party, and (optionally) industry/age cohort. The fewer inputs you have, the wider the result range.

Pre-relationship super growth illustration

See roughly what a pre-relationship balance could be worth today.

Enter the dates and balances you have. The tool projects the pre-cohabitation balance forward through an assumed return and compares it with your balance at separation. It is a mathematical illustration only — it does not show what either party keeps, and it is not a signed report.

Pre & post cohabitation dates

Start of cohabitation (pre/post boundary)

Date of separation (end of post-cohabitation period)

Valuation date (often = separation)

Pre & post cohabitation balances

Pre-cohabitation balance

From the member statement closest to the start of cohabitation.

Post-cohabitation balance (at separation)

Estimate the pre-cohabitation balance

Toggle on if you don't have a statement at the start of cohabitation — the tool uses a fixed A$28,000 placeholder so you can see how the illustration works. It is not an estimate of your balance and is not based on your fund or cohort.

Assumptions

Assumed net return (% p.a.)

% p.a.

Default 6.5% — long-run APRA balanced-option proxy. Reduce for conservative, increase for growth options.

Assumed split of post-cohabitation pool

Indicative only. Section 79 splits are matter-specific and based on contributions and future needs.

Glossary

Key terms used in this calculator

Plain-English definitions for the inputs and concepts behind a pre & post cohabitation superannuation split.

Cohabitation date: The date the relationship became a de facto or married cohabiting relationship — the boundary between pre-cohabitation super (generally non-marital) and post-cohabitation super (generally part of the matrimonial pool). Use the earliest of the move-in date, marriage date, or other clear evidence of cohabitation.
Pre-cohabitation balance: The member's superannuation balance on the cohabitation date, taken from the member statement closest to that date. This balance is rolled forward to the valuation date so it can be compared in today's dollars.
Post-cohabitation / matrimonial component: The portion of super accrued during the relationship — broadly, the balance at separation minus the pre-cohabitation balance grossed-up to today's dollars. This is the pool typically considered for splitting under s 79 / s 90SM of the Family Law Act.
Balance Benchmark Rating: The estimate used in a signed report when an opening statement cannot be recovered. It works from the member's earnings history, the super guarantee rate at the time and published fund returns, and reports a low / central / high range. This free calculator does not apply it — it uses a fixed placeholder instead.
Assumed net return: The annual after-fees, after-tax return used to gross-up the pre-cohabitation balance to the valuation date. The 6.5% default is a long-run proxy for an APRA balanced option — lower it for conservative options, raise it for high-growth options.
Assumed split of post-cohabitation pool: The percentage of the matrimonial component allocated to the non-member spouse for illustration. Real splits under s 79(4) / s 90SM(4) are matter-specific, weighing contributions, future needs and other factors — not a fixed 50/50.
Valuation date: The date balances are valued at — most commonly the date of separation, but it can be the hearing date or another agreed date. All projections in the calculator are expressed as at this date.
Sensitivity (±1.5%): We flex the assumed return up and down by 1.5 percentage points to show how dependent the estimate is on the return assumption. A formal report uses fund-specific actual returns or a documented benchmark with stated reliance.

Disclaimer. The estimator uses a single deterministic rate of return and simplified assumptions. It does not account for actual fund-specific returns, contributions, rollovers, fees, insurance premiums, defined-benefit factors, SMSF asset valuations, member tax components, or s 79(4) factors such as contributions and future needs. It is provided for general educational purposes. No actuary–client relationship is created by use of this tool. For an expert report suitable for mediation or court, contact us for a fixed-fee engagement.