FIRE Model API: …
FIRE Model

Know your FIRE age — clearly

Model your path with income, expenses, property, and super. Compare scenarios and see when your plan becomes self-funding — with a simple FIRE marker on the timeline.

No signup · Export CSV · General information only
FIRE marker
See the first point you become eligible.
Scenario comparisons
Rent vs buy, offset, PPOR vs investment.
Cashflow warning
Flags when cash goes negative.
General information only. Not financial advice.
No signup · Export CSV · General information only

What this does

This is your FIRE simulator UI. You enter assumptions + properties, the backend runs the monthly engine, and you get charts + tables to see when (or if) your plan becomes self-funding.

How to use it

1) Inputs — set your income/expenses, growth assumptions, and super settings.
2) Properties — add PPOR + investment properties (each has its own loan/rent/costs).
3) Results — view your net worth, cashflow, and the first point you become FIRE-eligible.

Key concepts (plain English)

Offset account: cash you hold reduces interest by “offsetting” your loan balance. Example: $100k cash against a $500k loan means interest is charged on ~$400k (not $500k).

Net rent: rent after property running costs (strata/rates/other) and (for investments) interest. It can be negative (negative gearing) or positive.

Principal vs interest: interest is a cost; principal is paying down the loan (it reduces your debt and builds equity).

FIRE income: the model estimates income after FIRE mainly from: investment property net rent + stock drawdown + (super drawdown once accessible), minus tax and principal servicing.
Tip: start with Yearly mode while you’re tuning assumptions (faster, cleaner). Use Monthly only for debugging.

Inputs

The settings you change most often.

Stocks and Super

Less common settings. Collapse when you’re not changing these.

Properties

Each property is its own card. Collapse this when you’re not editing.

Results

Run the model to see charts + tables.
Cash (end)
Stocks (end)
Property equity (end)
Net worth (end)
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Quick summary

Now / FIRE / End snapshot.

Summary table

Full series (cash/stocks/property/net worth). Click to expand.

Property breakdown

Per-property value/mortgage/equity + net rent. Click to expand.

Notice