Retirement Calculators: FIRE, 401(k), Roth, HSA

Retirement is the category where the compounding math on this site does its most dramatic work, and the seven calculators here answer the questions in the order people actually ask them: how big does my portfolio need to be, when does my savings rate get me there, what will I really have, which account keeps more of it, can a high earner still fund one, am I on track, and can healthcare money grow tax-free too. Together they cover the arc from first contribution to final balance.

Sizing the number

The FIRE calculator answers the question that comes before all others: how much money replaces your expenses. It applies the 4% rule to your annual spending to derive your financial-independence number, then works out how many years your current savings rate needs to get there. The result converts “retire early” from a vague ambition into a specific balance and a specific date, and every other retirement tool on this page exists to help reach that number. For a worked example of what hitting that number looks like in practice, see how to retire at 43.

The savings rate retirement date calculator runs the same engine from the opposite direction: instead of deriving your savings rate from a budget, it takes the rate itself as the dial — 10%, 20%, 50% — and prices the retirement date each one produces. The savings rate is the strongest retirement lever there is because it moves both sides of the equation at once, growing the contribution while shrinking the target, and this tool is the one that quantifies that leverage in years.

The retirement savings by age calculator checks progress against the Fidelity milestone staircase — 1× salary by 30, 3× by 40, 6× by 50, 8× by 60, 10× by 67 — and reports where the projection stands at every rung, which milestone is next, and the monthly deposit that closes any gap. It is the “am I on track” tool, and it pairs naturally with the FIRE calculator: one sizes the destination, the other checks the route.

Building and protecting the balance

The 401(k) calculator projects what a specific account will actually hold at retirement: contributions, a “50% up to 6%“-style employer match, and growth, reported in nominal dollars and in today’s dollars. The match is the free money inside the projection, and the chart draws the real balance alongside the nominal one so the inflation adjustment is visible, not asserted.

The Roth vs. Traditional IRA calculator answers the account-choice question on the only honest basis: the same out-of-pocket cost today, through both tax treatments, reporting the after-tax spendable balance each leaves at retirement. When the tax rate now equals the rate in retirement, the two tie exactly — the calculator shows why, and which way the answer leans when the rates differ.

High earners who earn too much to contribute to a Roth directly are not locked out, and the backdoor Roth IRA calculator is the tool that checks the trapdoor in the workaround: contribute nondeductibly to a Traditional IRA, convert to Roth — then watch the pro-rata rule pull existing pre-tax IRA balances into the conversion and report the tax bill and the balance that actually lands in the Roth. The move works cleanly only when pre-tax IRA balances are small, and this is the calculator that quantifies “cleanly.”

The HSA calculator is the stealth retirement tool: a health savings account projected to retirement with the full triple tax advantage — pre-tax in, tax-free growth, tax-free medical withdrawals — and a medical-spending dial that shows how much of the growth is surrendered to current-year healthcare bills. For anyone with access to one, it is the last account to spend and the first to max.

What the numbers have in common

Every tool here runs on the same growth engine as the rest of the site. The two planning tools — FIRE and the savings rate retirement date calculator — default to a 5% real, after-inflation return, because their targets are quoted in today’s dollars; the account projectors default to a 7% after-fee return, the honest middle of the historical nominal range. Either way the return assumption dominates every output. The category is designed to be used as a sequence: FIRE sizes the target, the savings rate calculator prices the pace, savings by age checks the route, the 401(k) and HSA calculators build the balance, and Roth vs. Traditional — with the backdoor Roth as the high-earner’s detour — decides which wrapper keeps more of it.

Where to go next

Retirement is the far end of every other category. The budgeting category produces the savings rate the FIRE calculator depends on; the compounding category is where the growth math is explained in isolation; and the savings category covers the shorter, less risky goals that come first. Retirement is what all of it becomes once the horizon passes a decade and the money is invested rather than merely saved.

Browse the full index of every calculator or the flat sitemap, or explore the other topics below.

That knock-on effect runs through every linked tool below. The budgeting surplus produces the savings rate the FIRE calculator depends on, the compound interest and Rule of 72 tools explain the growth math in isolation, the savings goal timeline and inflation-adjusted savings goal price the shorter goals that come first, and the net worth and emergency fund calculators keep the whole picture honest. When the horizon is short rather than career-length, the high-yield savings and certificate of deposit calculators are the right vehicles instead.