Project whether your retirement savings will last in Montana.
Simulates retirement: savings grow at the assumed return while you withdraw the yearly spend. The 4% rule suggests starting with ~25× spending.
Simulate
Balance = balance × (1+r) − spend, each year
Projection — returns are not guaranteed.
For 30-year horizons it has historically held in most markets; adjust for sequence risk and taxes.
Rates are approximate reference values. Local rates, exemptions and rules can differ, so treat the output as a planning figure only.