Understand the numbers behind your options.

FIRE: a spending-based benchmark

Divide an annual lifestyle budget by the selected planning withdrawal rate. For example, a $40,000 annual budget divided by 4% produces a $1,000,000 portfolio target. These illustrative numbers are not a withdrawal-rate recommendation.

FIRE target = annual spending ÷ planning withdrawal rate

Lean, Normal, Chubby, and Fat FIRE use different editable budgets. Targets are gross portfolio benchmarks. Account access, taxes, events, property cash flows, and changing future budgets are assessed in the full projection. Reaching a threshold once does not establish that all later expenses can be funded.

CoastFI: grow toward a later target

CoastFI discounts your Normal FIRE target to today at the assumed real return, through your target retirement age. It assumes no further deposits or withdrawals. Living costs must be covered elsewhere while that portfolio grows.

CoastFI target = FIRE target ÷ (1 + real return)^{years until retirement}

The milestone page recalculates this target at each projected age. It shows the first modeled crossing, which can be lost later.

GeoFI: a different budget, a different target

GeoFI applies the spending-based FIRE calculation to a destination’s lifestyle budget, including the chapter’s housing and healthcare additions. Location presets are editable examples, not live cost-of-living prices.

A move can also create one-time costs, new income, and a later return home. Model those in dated chapters and events. Currency movements, visas, and tax residency rules are not modeled.

Follow the plan month by month

Dated one-time costs, receipts, and property transactions are netted at month start. Investment returns follow, then regular income and spending at month end. If a chapter uses an explicit savings contribution, it replaces income minus base spending; it is not added twice.

The planner tracks account balances and property equity separately. Unsold property equity cannot fund portfolio withdrawals. A primary-home model can replace rent while adding mortgage payments and ownership costs; rental property can add income and expenses.

Chart details show financial periods ending at annual points, including any partial final year. Clicking an event highlights its exact date while the detail panel shows the cash-flow period containing it.

Today’s purchasing power and inflation

Inputs and primary results are expressed in today’s US dollars. If you enter a nominal return, the model removes inflation and then applies the configured annual return drag.

Real return = (1 + nominal return) ÷ (1 + inflation) − 1 − return drag

The nominal chart applies inflation once to convert portfolio values into future dollars. Chapter inflation relative to global inflation and explicit real spending growth can change purchasing power. Inflation is a selected assumption, not a random process in the market simulation.

Market success measures modeled funding

The simulation draws independent monthly lognormal returns calibrated to the selected annual arithmetic real-return mean and annual volatility. Success means every month is funded through the chosen horizon. An earlier funding shortfall remains a failure even if later income rebuilds the portfolio.

Percentile bands include failed paths. A portfolio ending a month at zero is different from an unpaid bill: spending the last dollar can still fully fund a month. Account-access limits can also leave a funding shortfall while other assets remain positive.

The sampling interval describes simulation noise, not confidence in a real-world retirement outcome. Markets are not modeled with changing regimes, asset correlations, or historical bootstrapping. Property assumptions are deterministic. Stress presets are illustrative sequences, not historical backtests. The optional return-to-work response assumes work begins immediately when triggered.

The Freedom Score is a product guide

The score averages five equally weighted, capped factors: Normal FIRE progress, lowest-cost lifestyle FI progress, current-lifestyle runway relative to ten years, current spending covered at the planning withdrawal rate, and CoastFI progress.

It runs from 0 to 100. It is not a probability, a scientific risk score, or a substitute for inspecting the full projection and market outcomes.

Escape Velocity is a separate growth threshold

This benchmark compares expected annual real portfolio growth with a lifestyle budget. It uses expected return rather than the planning withdrawal rate. Actual markets can decline for years, so expected growth covering expenses is not a withdrawal-safety test.

US taxes, account access, and Social Security

Withdrawal estimates use 2026 federal rules with configurable filing status, income context, state additions, cost basis, and account history. The model distinguishes taxable, pretax, Roth, HSA, and other supported accounts. Existing after-tax chapter budgets are not taxed again. Planning periods approximate tax years.

Social Security is optional. You can use assumed earnings or enter a statement’s gross benefit at full retirement age, then adjust claiming age. The estimator uses a frozen 2026 wage scale; it does not reconstruct historical wage indexing or establish your actual SSA eligibility. Spousal and survivor benefits, Medicare premiums, and post-claim benefit recomputation are not automatic. Manual pension income remains separate unless explicitly replaced.

Required minimum distributions, some early-distribution exceptions, tax credits, health-insurance subsidies, other debts, and future tax-law changes are among the omissions. Review account assumptions and use overrides where appropriate.

Saving, sharing, and privacy

Calculations run in your browser. Your plan and saved scenarios use this browser’s local storage; clearing it removes them. Export JSON for a portable copy. There is no account or bank connection.

Sharing the app includes no plan details. Selected-result links include your chosen results. Full-plan links expose the encoded plan to anyone receiving them. Encoding is not encryption. Shared plans open as temporary previews so they do not silently replace your existing plan.

Feedback includes the screen, app version, and what you explicitly type. Review it before sharing. Opening an email draft does not send it. Avoid account numbers and personal financial details. Hosting infrastructure may process technical request data; local calculation does not mean anonymous browsing.

Sources and example data

The household example rounds separate income and investable-asset percentiles from the Federal Reserve’s 2022 Survey of Consumer Finances. These are marginal percentiles in 2022 dollars, not one observed household or a recommendation for your budget.

• Federal Reserve: Survey of Consumer Finances
• NIST: lognormal distribution and binomial proportion intervals
• IRS: 2026 federal inflation adjustments
• IRS: IRA distributions and early-distribution exceptions
• IRS: HSAs and net investment income tax
• SSA: get a benefits estimate, 2026 figures, and claiming-age adjustments
• IRS: taxation of Social Security benefits