One timeline, every decision. It crushes your debt, redirects what frees up into investing, finds the best Social Security claiming age, and solves for the earliest age you can actually retire — and confirms the money lasts.
One engine, two phases with detailed tax tracking. Before retirement, your savings compound at the growth rate while you invest each month; after retirement, the portfolio earns the (usually lower) drawdown return while you withdraw what your spending needs beyond your income. Everything sits on a single age timeline, and the retirement years are broken down into an annual cash flow table showing every income stream, expense, and tax.
Debt first, then redirect. Your debts are paid highest-rate-first (the avalanche method, which minimizes total interest). The full amount you were paying toward them — minimums plus your extra — is then redirected into investing the moment they clear, which is where a surprising amount of the plan's power comes from. The model assumes those payments come from your working income, so it's built around clearing debt before the retirement date it recommends.
Federal income tax calculated annually. For each year in retirement, the calculator computes taxable income from your pension, a portion of Social Security (using the official 0–85% formula, with the taxability thresholds set by your filing status — $25k/$34k single, $32k/$44k married), other income, and your 401(k) drawdown — a traditional-account withdrawal, taxed as ordinary income. That income is reduced by your standard deduction (a 2026 base figure that grows each year with your inflation rate — the same index applied to the federal brackets, so the two stay in step), then taxed using 2024 federal brackets adjusted for inflation each year. From age 65 on, the calculator automatically adds the IRS age-65+ additional standard deduction ($1,650 per spouse for joint filers — both spouses assumed 65+ — or $2,050 single, for 2026, escalated alongside the base). The separate, temporary OBBBA "senior bonus" deduction ($6,000 per person 65+, for tax years 2025–2028, phased out at higher incomes) is not modeled, so a low-to-moderate-income couple in those specific years would owe a bit less than shown. You choose Single or Married filing jointly. State tax is applied at a flat rate you set, on your income excluding Social Security — most states, Virginia included, exempt Social Security from state income tax, so it's removed from the state base. Virginia defaults to 5.75% (its top bracket); adjust the rate for your own state or use a blended rate. This stays a flat-rate approximation: it doesn't model state-specific deductions such as Virginia's 65+ age deduction or its graduated lower brackets, so treat it as close rather than exact.
Annual cash flow table. For each retirement year the table totals your guaranteed income (Pension + Social Security + Other) and your total expenses (Federal tax, State tax, Debt until cleared, Living, Medical), and shows the Drawdown — the cash pulled from your 401(k) to cover the gap, equal to Total Expenses minus Total Income. The 401(k) keeps compounding untaxed inside the account; only the drawdown is taxed, as ordinary income. Because the withdrawal is itself taxable and also nudges more of your Social Security into the taxable column, the drawdown and the tax on it are solved together each year rather than one before the other. One thing that surprises people: your balance can rise in a year you also drew from it, because the untaxed growth on the account outran what you pulled out. The model withdraws only what your spending needs and does not yet add required minimum distributions (RMDs), which force extra taxable withdrawals starting at 73–75 — relevant only if your guaranteed income already covers most of your spending.
Inflation, honestly. Living and taxes grow with general inflation; medical grows at its own faster rate; Social Security always carries a COLA; pensions and other income only do if you tick the box. You can also step living expenses down at future ages — say when a mortgage is paid off — and each new amount (entered in today's dollars) holds its real value and inflates from there. Standard deduction and federal brackets are also escalated by inflation each year. The chart and headline default to today's dollars so the numbers reflect real buying power, not inflated figures that just look big.
Social Security earnings test. If you claim Social Security before your full retirement age and tick "other income is earned," the model applies the IRS earnings test: for years before FRA, $1 of benefit is withheld for every $2 of earnings above the annual limit (an editable field, set to the 2026 figure of $24,480, which then grows with inflation across the projection — update it each year when SSA announces the new number). The test only touches earned income — wages and self-employment — never pensions or investments, so leave the box unticked for passive income. Withheld benefits aren't lost: at FRA the model credits the withheld months back, recomputing your benefit as if you had claimed that many months later, which permanently lifts it from FRA on (you'll see Social Security step up at 67). The partial earnings test in the year you reach FRA is approximated as no test.
Returns are assumed steady; real markets don't behave that way, so a plan that only barely survives should be treated as a yellow flag. Tax calculations are simplified (no capital gains treatment, no state tax brackets, no deductions beyond standard) — this is a planning tool, not a full tax return.