Coast Retirement · Research

How Coast Retirement calculators work

Coast Retirement stores your baseline once (income, savings, expenses, properties), then runs Python-powered projections for Coast FIRE, drawdown, ACA, and scenarios with visible assumptions.

What this means

One source of truth feeds every model so you do not re-enter data. Outputs are deterministic unless a model explicitly runs simulations.

How it works

Enter baseline on retirement model (or use quick calc on homepage).
Recalculate to refresh year-by-year projections.
Open Models tab for NPV of expenses vs 4% SWR benchmarks.
Use Scenarios for persona flows and specialized tools.

Example

Section 5 expense rows drive NPV of lifestyle + housing; Models compares lump sum needed today to 25× today's spending.

Assumptions

Defaults shown on screen (e.g. 7% real, 4% SWR on quick calc)
User-editable where noted
Projection can extend through age 90 when enabled

Limitations

Not tax advice; ACA and Roth tools are educational. Markets are not forecast with certainty.

Common mistakes

Comparing NPV to SWR without reading horizon labels
Skipping recalc after editing expenses
Treating models as guarantees

Related tools

FAQ

Is data stored?

Account optional; baseline saved when you sign in.

What backend runs the math?

Python engine behind /coast/ API endpoints.

Can I export?

Projection CSV from the planner Summary section.

Difference from spreadsheet?

Integrated expenses, properties, and scenario links.

Is this advice?

No — educational models only.

Open the full retirement planner →

CoastRetirement.com provides educational calculators and planning models. It does not provide individualized financial, investment, tax, or legal advice. Calculator outputs depend on user-provided assumptions and are not guarantees of future results. Consult a qualified professional before making financial or tax decisions.