Coast FIRE Calculator
↻ Updated 2026Find out how much you need invested today to stop contributing forever and still hit your retirement number — with a year-by-year projection, return sensitivity, Social Security and pension offsets, and a CSV you can keep.
Educational calculators — always consult a licensed professional before making financial decisions.
Your $145,000 alone grows to $991,886 by age 65, leaving a $508,114 gap against the $1,500,000 target. Keep contributing $24,000 a year and you clear it at age 36.
Coasting is a deadline, not a destination. The number you need in hand shrinks the earlier you hit it, because compounding has longer to work — which is why the same plan is far cheaper at 30 than at 45.
Target at your assumption: $1,500,000. The target itself barely moves between these rows — the withdrawal rate sets it. What moves is how long it takes to get there, and two percentage points of return is usually worth several years.
No Social Security or pension entered, so the portfolio is carrying all $1,500,000of the target on its own. If you expect either, adding it above will cut the number materially — most people's Social Security is worth several hundred thousand dollars of portfolio they therefore do not need to build.
Runs entirely in your browser — nothing you enter is sent to us.How this works
How to read your Coast FIRE result
Coast FIRE is the only variant that answers "when can I stop saving" rather than "when can I stop working". On the defaults, $145,000 at 32 grows to $991,886 by 65 at 6% real — short of the $1.5m target, and the page says so, along with the age at which continuing to contribute closes the gap. The headline number is what you'd need invested today to never save another dollar.
How the Coast FIRE number is calculated
Two steps. First the target: your annual retirement spending divided by your withdrawal rate, less the present value of any Social Security or pension you expect. Then the coast number: that target discounted back to today at your expected real return, over the years until you retire.
The second step is the whole idea. If money compounds at 6% real, a dollar today is worth 1.06^n dollars in n years — so the amount you need in hand now is the target divided by that same factor. Once you hold it, arithmetic does the rest without you.
target = annual spending ÷ withdrawal rate − value of deferred income years = retirement age − current age coast number = target ÷ (1 + real return)^years you have coasted when: invested today ≥ coast number projected at retirement = invested today × (1 + real return)^years Deferred income (Social Security, pension) is valued as an annuity that starts later and stops at the end of the plan — NOT as a perpetuity: PV = benefit × [1 − (1+r)^−(endAge − startAge)] ÷ r × (1+r)^−(startAge − age)
- annual spending
- What you expect to spend each year in retirement, today's dollars — the single largest driver of the target — a 10% change moves it 10%
- withdrawal rate
- The share of the portfolio you draw each year — 4% is the Trinity Study convention; lower rates mean a larger target and a longer horizon
- real return
- Expected return after inflation — using a real return is what lets every other figure stay in today's dollars
- years
- Runway between now and your retirement age — the exponent — which is why age matters more here than in any other FIRE variant
- coast number
- What you need invested today to stop contributing — not what you need to retire; that is the target
The discount is doing something that deserves stating plainly: it assumes your money earns the real return you entered, on average, every year until retirement. Over thirty years that is a reasonable planning assumption. Over eight it is a bet. Coast FIRE calculated at 55 for a retirement at 65 is far more fragile than the same calculation at 30, and no calculator can show you that in a single number.
It also says nothing about sequence-of-returns risk, which is what actually ends retirements — the order returns arrive in, not their average. The safe withdrawal rate calculator is where that question lives.
Worked examples
Example: $145,000 at 32, retiring at 65
The calculator's defaults — $145,000 invested, $24,000 a year going in, $60,000 of retirement spending, 6% real return, 4% withdrawal rate, no Social Security entered.
| Target$60,000 ÷ 4% | $1,500,000 |
| Years to retirement65 − 32 | 33 |
| Discount factor | 1.06^33 ≈ 6.84 |
| Coast number today$1,500,000 ÷ 6.84 | $219,279 |
| You have$74,279 short | $145,000 |
| Left alone, that becomesby age 65 — short of target | $991,886 |
| Keep contributing and you coast atfour more years of saving | age 36 |
Four more years of contributions buys the right to stop entirely. That is the Coast FIRE proposition: not thirty-three more years of saving, but four — after which the job only has to cover this year's rent, and every further dollar invested is a choice rather than an obligation.
Example: the same plan, started at 42
Identical numbers, ten years later. The target has not moved; the runway has.
| Targetunchanged | $1,500,000 |
| Years to retirement | 23 |
| Discount factor | 1.06^23 ≈ 3.82 |
| Coast number todaywas $219,279 at 32 | $392,696 |
| Increasefor a ten-year delay | +$173,417 |
The same retirement costs $173,417 more to coast to, ten years later — a 79% increase for a delay of less than a third of the runway. Nothing about the plan changed except how long compounding has to work. This is the clearest argument the FIRE movement has, and it is entirely a property of the exponent.
Frequently asked questions
What is Coast FIRE?
The point at which your existing investments, left completely alone, will grow to your full retirement number by the time you retire. You still work and still cover your living costs from income — but you never have to make another retirement contribution.
It is the earliest of the FIRE milestones and by far the easiest to reach, which is why it appeals to people who find full FIRE implausible. On this page's defaults it arrives at 36 rather than the mid-50s that full financial independence would require.
Is Coast FIRE the same as being retired?
No, and the distinction matters. Coasting means your retirement is funded; it does not mean your life is. Your job still has to cover rent, food, insurance and everything else you spend today — the only thing that stops is saving for later.
In practice that usually means you can take a pay cut, work fewer hours, or move to work you prefer, because the income requirement has dropped to current spending. What it does not mean is that you can stop working, which is Barista or full FIRE.
What return should I use for Coast FIRE?
A real return — after inflation — is the only sensible choice, because it lets your spending figure stay in today's dollars. Long-run US equity returns have run around 7% real historically, but that is a historical average over a very long window and includes periods where a decade returned nothing.
The sensitivity panel on this page exists for exactly this reason. Run the plan at 5% as well as 7% and see how far the coast age moves; if the answer is more than a few years, the plan is leaning on the return assumption rather than on your savings.
Should I include Social Security in my Coast FIRE number?
If you expect to receive it, including it is more accurate than ignoring it — but the way most calculators include it is wrong. A $30,000 benefit starting at 67 is not $750,000 off your target. It starts decades from now and stops when the plan does, so its present value is considerably less.
This page discounts it properly as a deferred annuity running to age 95. Enter it and you will see the target fall, but by less than the naive figure — which is the honest answer and the conservative one.
How is Coast FIRE different from Barista FIRE?
Coast FIRE is about contributions; Barista FIRE is about income. Coasting means you have stopped saving but still work full-time to cover current costs. Barista FIRE means you have stopped working full-time, and part-time income covers part of your spending while the portfolio covers the rest.
Coast comes first and is much cheaper to reach. Most people who pursue both hit Coast FIRE years before Barista becomes viable.
What this Coast FIRE calculator doesn't handle
One growth rate, one horizon, no tax. Real portfolios are messier than that.
- Average returns, not real ones — The discount assumes your real return arrives smoothly every year. Markets do not work that way, and a poor decade early in the coast period leaves you short with no contributions running to make it up. The shorter your runway, the more this matters.
- No tax modelling — The target is stated as spending, not as withdrawals. Money coming out of a traditional 401(k) or IRA is ordinary income, so the portfolio needed to fund a given lifestyle is larger than shown here — potentially much larger at higher spending levels.
- Contributions are annual and level — Real contributions rise with income, pause during career breaks, and jump when a mortgage clears. The projection adds the same amount at the end of every year.
- Inflation is assumed uniform — Using a real return treats your personal inflation as matching the index. Healthcare and housing have historically outrun it, and both are large in retirement.
- Employer match and vesting — Not modelled. If part of your contribution is a match you would lose by stopping, the true cost of coasting is higher than the page implies.
- Not financial advice — This is an educational estimate built from assumptions you supply. It is not a recommendation to stop saving, and the decision to do so deserves a licensed professional who knows your full position.
- ·Trinity Study / 4% safe withdrawal rate — Bengen (1994) and the Trinity Study (1998) — basis for the 4% rule
Rates, brackets and limits here are checked against primary sources. If a number still looks off, email support@realmoneyiq.com and we'll review and fix it.
RealMoneyIQ provides free educational calculators, not financial, tax, investment or legal advice. Results are estimates based on the assumptions you enter and publicly published rates; your actual outcome will differ. Always confirm decisions with a licensed professional who knows your full situation.