Financial freedom calculator — prototype

Drag the sliders. Figures are in today's dollars (inflation-adjusted) and reflect the assumptions in "How we calculated this" below — not a guarantee.

Lean FIRE

Coast FIRE

Barista FIRE

Fat FIRE

Custom

Current age 28

Used as the starting point for every projection below.

Current invested savings $15,000

Everything you've already got invested or saved toward this goal — cash, brokerage, retirement accounts. Type an exact figure if the slider's too coarse.

Current high-interest debt (optional) $0

Credit cards, personal loans — assumed at a representative 18% APR. Your savings pay this off first before investing starts.

Monthly savings $800

What you actually put toward savings and investing each month, on top of what's already saved.

Target annual spending in retirement $40,000

What you expect to actually spend per year once retired, in today's dollars. Type an exact figure if the slider's too coarse.

Stock allocation 80%

Higher stock allocation means higher expected growth but a bumpier ride — drives the return used in the Monte Carlo simulation.

Safe withdrawal rate (used for your target number)

How much of your portfolio you draw down each year in retirement. Lower % is more conservative, higher % is more aggressive.

Years to financial freedom —

Your FIRE number (range) —

30-year retirement success rate —

Median path Optimistic / pessimistic band Target number

How we calculated this

This is a prototype. It models the accumulation phase with a blended real (inflation-adjusted) return based on your stock/bond mix (stocks ≈7% real, bonds ≈2.5% real), and runs 400 simulated markets (Monte Carlo, annual steps, normally distributed returns) to show a realistic range of outcomes instead of one straight line.

Safe withdrawal rate range (3.9%–5.25%): 3.9% reflects Morningstar's more conservative 2026 estimate; 5.25% reflects William Bengen's own updated, more optimistic figure. Your selected rate sets the target number used for the timeline; the range shown is the honest spread between current expert estimates.
30-year retirement success rate: a separate 400-simulation Monte Carlo test of your target number being drawn down at your chosen spending level over a 30-year retirement, to illustrate sequence-of-returns risk — a bad market in your first few retirement years is far more dangerous than the same drop later on.
Debt payoff: if you enter a debt balance, we assume a representative 18% APR and route your monthly savings to payoff first; investing (and the Monte Carlo chart) begins once you're debt-free.
Barista FIRE: assumes $18,000/year of part-time income offsets your spending target, so your portfolio only needs to cover the rest.
Coast FIRE: shows how much you'd need invested today for growth alone to reach your number by age 65, with no further contributions.
This is a simplified, illustrative model — not personalized financial, investment, tax, or legal advice. Real plans should account for your full financial picture.