Guide

How your plan is saved

RetirFi needs no account and no login. Everything you enter saves automatically to this browser's local storage. Your data never leaves your device unless you choose to back it up.

Because it lives in the browser, clearing your cache or switching devices will lose the plan. Use Save Plan in the header to email yourself a restore link, or copy a shareable link to reopen your plan anywhere.

The setup wizard & sample plan

On your first visit a short guided wizard collects the essentials. You can re-run a fully worked example any time with Load Sample (the Alex & Jordan household) to see how a complete plan looks, then Reset to start blank.

Loans & mortgages: don't double-count

Enter every loan (mortgage, car, student debt) in the Liabilities section. RetirFi amortizes each one and subtracts the payment from your cash flow automatically, then stops it once the loan is paid off. If you also list that payment as an expense, it's counted twice and your free cash flow and projection will be wrong.

Your Expenses section should hold only living costs: groceries, utilities, insurance, travel, and so on. Property tax and homeowner's insurance belong in the mortgage's escrow field, not as separate expenses.

Adding an employer 401(k) match

On the retirement account in Assets, enable the employer-match option and set two numbers:

• Match percentage: how much your employer matches (e.g. 50%).
• Match-up-to limit: the share of your salary they'll match against (e.g. 6%).

The match is your contribution, capped at salary × match-up-to %, times the match %. So a 50% match up to 6% of a $100,000 salary (with you contributing at least $6,000) adds $3,000/year on top of your own contribution in every simulation year.

Contributions & IRS caps

You can fund an account two ways: enter a flat dollar contribution directly on the account, or link it to an income source as a percentage of that income, so it scales with raises and stops when that income stops at retirement.

Either way, contributions are capped at the IRS annual limit for that account type (401(k) vs. IRA), including age-based catch-up amounts, so an oversized entry can't inflate your savings. 529 college accounts count toward net worth but are excluded from retirement drawdown, since they're earmarked for education.

Excess cash flow: investing your surplus

Whatever is left of your take-home pay after living expenses, debt payments, and account contributions is your excess cash flow. By default the simulation treats it as spent. The Excess Cash Flow Allocation card lets you invest some or all of it instead, split by percentage or fixed dollars across your accounts and added on top of your contributions in every pre-retirement simulation year.

The card lives in two places: on the Income & Expenses page below your expense list, and on the Dashboard behind ⚙ Configure allocation. They're the same setting, so a change in either place updates both.

If you entered your monthly spending in the setup wizard, this is already switched on: the wizard directs 100% of your surplus into your brokerage account. Adjust the split any time.

Your home & real estate

Add your home as a real-estate asset and link it to its mortgage in Liabilities. Net worth then correctly nets the home value against the loan balance, and the home isn't treated as a liquid account. Only cash, brokerage, and retirement accounts are spent down in retirement; real estate stays on the balance sheet.

Retirement age & spending goal

Two inputs drive the whole projection: your retirement age and your monthly income goal (target retirement spending). The spending goal is required. Without it there's nothing for the simulation to fund. Enter it in today's dollars; RetirFi inflates it forward for you.

Social Security: estimate vs. manual

RetirFi estimates your benefit from your income and years worked using the SSA's PIA formula. It's a reasonable approximation, but your real benefit depends on your full 35-year earnings record. For accuracy, look up your number at ssa.gov/myaccount and switch the card to Manual to enter it directly.

Your claim age (62 / 67 / 70) changes the benefit: earlier means smaller checks, later means larger. The break-even is usually around age 80–82.

Spouse & survivor modeling

Turn on Include spouse to model two people. The plan then runs to the second death. When the first spouse dies, Social Security switches to the higher survivor benefit, household spending drops by a percentage you set, and tax filing changes to single.

The control bar & assumptions

The bar at the top of the Monte Carlo tab sets your assumptions: dollar mode, retirement spending, lifespan(s), inflation, and number of simulations. More simulations = more precise but slower. 200 is a good balance, 1,000 is the most precise. Press Run to simulate.

What "probability of success" means

It's the share of simulated futures in which your portfolio doesn't run to zero before the end of your plan. 85% means your money lasted in 85 of every 100 simulated market histories. Planners commonly target 80–90%. Higher isn't always better, since a 99% result often means you're underspending and will leave a lot unspent.

Real vs. nominal dollars

Nominal dollars are the raw future numbers your statement will show. Real dollars are inflation-adjusted to today's purchasing power. At 2.5% inflation, $1M in 30 years buys roughly what $480K buys today. Toggle between them in the control bar.

Scenario compare & Plan Insights

Compare a scenario lets you build a "Scenario B" (retire earlier, claim Social Security later, or spend differently) and overlays it on your current plan so you can see the difference. Plan Insights works backward from a target success rate to find your max safe spending, earliest retirement age, and the single changes that move your odds the most.

Reading the chart & table

The Year by Year tab replays your latest Monte Carlo run as a timeline. Run a simulation first; the tab stays empty until you do. The chart stacks your account balances over the whole plan, colored by tax type, so you can watch taxable money spend down first while Roth is preserved.

The table below flips the usual layout. Accounts are rows and years are columns, stepping in five-year jumps. Milestone years (retirement, each planned event, the first death, plan end) are always included and tagged. Use the ‹ › arrows or the dots to page through five columns at a time.

Click the Portfolio, Income, or Spending row to expand it. Portfolio breaks out each account, Income splits into your income sources plus Social Security and RMDs, and Spending itemizes your expenses and debt payments.

Choosing a scenario & dollar mode

The Scenario picker chooses which simulated future you're viewing, from Bull (90th percentile) down to Bear (10th). The default, Median (50th), is the middle outcome, with half the simulated futures doing better and half worse. Switch to Bear to see the same plan under persistently poor markets, the stress test that matters most.

The Dollars toggle works like the one on the Monte Carlo tab. Nominal shows raw future dollars; Today's $ discounts every figure by your inflation assumption so amounts stay comparable to your current budget.

Where the numbers come from

Every column is one representative simulated path from your latest run, not an average of all runs. Retirement-year figures (Social Security, RMDs, taxes, spending) come straight from that simulation. For working years the simulation tracks only balances, so the table rebuilds your earned income from your Income entries, applying their growth rates and start, end, and stop-at-retirement settings, and estimates tax from your effective take-home rate.

Expense line items are prorated. The engine models one spending total per year, and the table splits it across your expense entries by their share of the budget. And because each run draws fresh random returns, the numbers shift slightly every time you re-run the simulation.

Linked fields & overrides

The tab holds two what-if tools, a Contribution comparison (Roth vs. Traditional) and a multi-year Conversion planner. Both are read-only; nothing you do here changes your plan.

Every input auto-fills from your plan, and the small badge next to each field says where the value came from ("your marginal rate", "retire at 65", "Monte Carlo median"). Type over any field to test a what-if; the badge flips to overridden · reset ↺, and clicking it relinks the field to your plan. The retirement tax rate is the one field that improves with a Monte Carlo run. With a run available it uses the effective federal rate along your median path; otherwise it falls back to an estimate from your spending goal and the tax brackets.

Contribution: Roth vs. Traditional

The tool answers one question. For the same yearly dollars into each account, which leaves more after-tax spending money at retirement? Five inputs drive it, and each defaults from your plan. They are your annual contribution, years until retirement, growth rate, tax rate today, and tax rate in retirement.

The model puts the same dollars into each account every year, so both grow to an identical pre-tax balance. Roth withdrawals come out tax-free. The Traditional balance is taxed at your retirement rate on the way out, but the deductible contribution also saves you tax today (contribution × current rate). The checkbox decides what happens to that saving. Invest some or all of it in a taxable side account (gains taxed at a 15% capital-gains rate) and it counts toward the Traditional column; spend it and it's gone.

The bottom row, Total after-tax value, is the verdict. The usual pattern holds. A higher tax rate today than in retirement favors Traditional, the reverse favors Roth, and whether you actually invest the tax savings often decides close cases.

Conversion: the multi-year planner

A Roth conversion moves money out of a Traditional (pre-tax) account into Roth, paying ordinary income tax now to avoid it later. The planner needs a Monte Carlo run first, because it reads your median path year by year (income, tax bracket, pre-tax balance) to find the years where converting is cheapest.

The banner highlights your low-income window, the years after you retire but before RMDs begin, when your taxable income and bracket dip. Each eligible year appears as a chip; click chips to add or remove years, and the "best" tags mark the years with the most bracket room. Pick an auto-fill target and every selected year converts just enough to reach the top of that bracket after its other income (earned income, RMDs, and the taxable share of Social Security). You can also type an exact amount into any row of the schedule.

Leave pay the conversion tax from outside cash checked to let the full conversion keep compounding tax-free. Uncheck it and the tax comes out of the converted amount itself, so less lands in the Roth.

The payoff table compares two futures at your plan's end. Converted dollars grow tax-free with no RMDs. Dollars left in Traditional face RMDs from age 73 or 75, each forced withdrawal taxed at that year's bracket on top of your simulated income and the after-tax remainder reinvested; whatever is still inside at the end is taxed at your blended retirement rate. If you'd have paid the conversion tax from outside cash, the leave-in column keeps and invests that cash too, so both paths compare equal dollars. A positive benefit means the schedule pays for itself; a negative one means you're converting too much or filling too high a bracket.

Assumptions & limits

Both tools use 2024 federal brackets and standard deductions for your filing status, a single blended 15% capital-gains rate on taxable side accounts, and SECURE 2.0 RMD rules. They ignore state income tax, IRMAA Medicare surcharges, ACA premium subsidies, the Roth five-year rule, IRA deduction phase-outs, and the step-up in basis at death. Treat the output as an educational estimate, not tax advice.

Market returns & Monte Carlo

Instead of assuming one fixed return, RetirFi runs hundreds of futures with randomized year-to-year market shocks, capturing the sequence-of-returns risk that fixed-rate calculators miss. For the full explanation, see Monte Carlo, explained →

Tax-aware drawdown order

In retirement, accounts are spent down tax-efficiently in this order: Taxable → Cash → Traditional → Roth. This preserves tax-advantaged growth as long as possible. Pre-tax (traditional) contributions also reduce your taxable income while you're working.

RMDs & taxes

Required Minimum Distributions from traditional accounts begin at age 73 or 75 (per SECURE 2.0, based on your birth year) and are modeled automatically, including their tax impact. Take-home pay is derived from federal and FICA taxes for your filing status.

RetirFi is an educational tool, not financial advice.