Coast FIRE Calculator — United States
Coast FIRE is the milestone most people hit years before they realise. Once your existing investments are large enough to compound into your full FIRE number by your target retirement age, every further contribution is optional — you only need to cover your living costs.
Your situation
All figures in today's dollars.
What you have and what you add
What you need invested today to coast
$415,577
You have $225,000 invested, so you are $190,577 short of the coast line. At your current contributions you cross it at age 45.
- Full FIRE number
- $1,500,000
- Coast FIRE age
- Age 45
- Time to coast
- 10 years
General information, not advice
Your balance against the coast line
Once the projection crosses the coast line you could stop contributing entirely and still land on your number.
- Projected balance
- Coast FIRE line
- Projected at retirement
- $2,149,460
- In brokerage
- $865,080
- In 401(k)
- $1,284,380
If you keep contributing
Reachable at any age
Locked until 59½
Assumptions and limitations
Every result above rests on these assumptions, and each can be changed in the inputs. Why the defaults are reasonable
- Return
- 8.0% a year, before fees
- Fees
- 0.10% a year
- Inflation
- 2.5% a year
- Withdrawal rate
- 4.0%
- Preservation age
- 59½
Limitations
- One steady return. Both pools grow at the same rate every year. Real returns vary, and a poor run before retirement would leave you short of the number even if the long-run average holds.
- No tax and no contribution limits. Contributions are taken as you enter them and are not checked against caps. Tax on investment earnings outside a 401(k) is not modelled, so their growth may be overstated.
- It stops at your retirement age. It does not test whether the money then lasts through retirement. The FIRE calculator and the drawdown simulator do.
The coast number at every age
Read across to see how much less you would need if you pushed your retirement date back — or how much more if you brought it forward.
| Age | Coast number | Projected | Status |
|---|---|---|---|
| 35 | $415,577 | $225,000 | Keep saving |
| 36 | $437,471 | $263,854 | Keep saving |
| 37 | $460,518 | $304,754 | Keep saving |
| 38 | $484,780 | $347,810 | Keep saving |
| 39 | $510,319 | $393,133 | Keep saving |
| 40 | $537,205 | $440,845 | Keep saving |
| 41 | $565,506 | $491,070 | Keep saving |
| 42 | $595,299 | $543,941 | Keep saving |
| 43 | $626,661 | $599,597 | Keep saving |
| 44 | $659,675 | $658,185 | Keep saving |
| 45 | $694,429 | $719,861 | Coasting |
| 46 | $731,013 | $784,785 | Coasting |
| 47 | $769,525 | $853,130 | Coasting |
| 48 | $810,066 | $925,075 | Coasting |
| 49 | $852,742 | $1,000,811 | Coasting |
| 50 | $897,667 | $1,080,536 | Coasting |
| 51 | $944,959 | $1,164,462 | Coasting |
| 52 | $994,742 | $1,252,810 | Coasting |
| 53 | $1,047,148 | $1,345,811 | Coasting |
| 54 | $1,102,315 | $1,443,713 | Coasting |
| 55 | $1,160,388 | $1,546,772 | Coasting |
| 56 | $1,221,521 | $1,655,260 | Coasting |
| 57 | $1,285,874 | $1,769,464 | Coasting |
| 58 | $1,353,618 | $1,889,684 | Coasting |
| 59 | $1,424,930 | $2,016,239 | Coasting |
| 60 | $1,500,000 | $2,149,460 | Coasting |
How this works
Can I stop saving and still retire on time?
The formula behind it
Your coast number is your FIRE number discounted back at the real rate of return: annual spending divided by your withdrawal rate, then divided by (1 + real return) raised to the number of years left. Everything is computed in today's dollars, which is why the real return — your nominal return less inflation — is what matters.
Why it changes how work feels
Coast FIRE turns a decades-long obligation into a much smaller one: cover this year's expenses. That is what makes a lower-paid but better job, a sabbatical, or dropping to four days a week suddenly affordable, long before full financial independence arrives.
The catch this page checks for
Most coast calculators quietly assume you can reach all of your money. If you plan to retire before your preservation age, part of that balance is locked away, and clearing the coast line does not mean you can actually stop working. The bridge panel tests whether your accessible pool covers the gap years.
What it deliberately ignores
Coast FIRE answers exactly one question: when can contributions stop. It does not model tax on the way in, contribution caps, or a variable market. Use the full FIRE calculator once you want the complete picture.
What Coast FIRE means in the US
Coast FIRE is the point where what you have already invested will grow into your full FIRE number by your retirement age without another dollar from you. From then on, work only has to pay for the present: rent, groceries, insurance.
In the US one thing changes when you coast: the employer match. A match is paid only on what you defer, so if your own 401(k) contributions stop, the match stops with them. If you keep deferring enough to collect it while coasting, enter that as your retirement contribution and set the brokerage contribution to zero to see the effect.
Coasting to 59½, or to an earlier age
A single coast number hides a timing problem. 401(k) and IRA money generally carries a 10% additional tax before 59½ (IRS), so if your target retirement age is earlier, part of your FIRE number has to be in a brokerage account or another source you can reach. The calculator shows the coast number for the whole portfolio, then runs a bridge test on the accessible part.
With a retirement age of 60, the default here, the bridge test has nothing to cover. With an earlier one, you can clear the coast line and still fail the bridge, because the growth is happening in accounts you cannot touch yet. The Rule of 55 and 72(t) payments can shorten the bridge, with conditions.
A worked example with real numbers
Take the calculator’s starting scenario: a 35-year-old with $225,000 invested, adding $27,000 a year, who wants $60,000 a year from 60.
- The FIRE number is $60,000 ÷ 4% = $1,500,000.
- The real return is the return after fees, adjusted for inflation: (8% − 0.1%) against 2.5% inflation is about 5.3% a year.
- Discounting the FIRE number back 25 years at that rate gives the coast number: $1,500,000 ÷ (1 + 5.3%)25 ≈ $415,577.
- With $225,000 invested today, the gap is $190,577. Keeping up $27,000 a year closes it at 45, 10 years from now. From then on, contributions are optional.
These are the calculator’s defaults, not a recommendation. Enter your own figures above to see yours.
Returns, fees and inflation
The coast number discounts your FIRE number back over decades, so it is very sensitive to the return you assume. The default is 8% before fees, 0.1% in fees and 2.5% inflation, which gives a real return of about 5.3%.
Over 25 years, a real return one point lower raises the coast number by roughly a quarter. Your plan's fund menu and your brokerage statements show what you actually pay, and entering those figures gives a more meaningful number than the default.
What coasting looks like in practice
Reaching Coast FIRE does not mean you can retire. It means the rest of your career only has to fund the present, which is what makes a lower-paid job, a sabbatical or fewer hours affordable. The thing most often underestimated is health insurance: leaving an employer plan means paying for coverage yourself, so price it into your spending first.
To model part-time income through to retirement, use the Barista FIRE calculator; to check the money lasts once you stop, use the FIRE calculator.
Frequently asked questions
How is the Coast FIRE number calculated?
It is your FIRE number discounted back to today at the real rate of return: annual retirement spending divided by your withdrawal rate, then divided by (1 + real return) raised to the years until retirement. With $60,000 of spending, a 4% withdrawal rate, 25 years to go and a real return of about 5.3%, it comes to around $416,000.
Does my 401(k) count towards Coast FIRE?
Yes. It keeps compounding whether or not you add to it. What it cannot do without an exception is pay for anything before 59½, which is why the calculator tests the bridge separately when your retirement age is earlier.
Do I lose the employer match if I coast?
The match is paid on your own deferrals, so it stops when they stop. Many coasters keep deferring enough to collect the match; enter that contribution and the match it earns as your retirement contribution to model it.
Which retirement age does the calculator start with?
60, so the default plan has no bridge to fund. You can set any age; before 59½, the bridge test checks whether your brokerage account covers the gap.
What's the difference between Coast FIRE and Barista FIRE?
Coast FIRE is a milestone: your investments will reach the full FIRE number on their own, so work only funds the present. Barista FIRE is a plan: leave full-time work early and cover part of your spending with part-time income while the portfolio covers the rest. The Barista FIRE calculator models it with US tax rules.
Sources
- IRS Topic 558: Additional tax on early distributions from retirement plans other than IRAs
- IRS: Exceptions to tax on early distributions
- IRS: 401(k) and profit-sharing plan contribution limits
- Cooley, Hubbard and Walz (1998), Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable (the Trinity study), AAII Journal
Keep going
Other American calculators
FIRE
The full projection: earliest retirement age, the bridge years, and whether the money lasts.
Barista FIRE
Model part-time income covering part of your spending while the portfolio keeps growing.
Lean FIRE
Independence on a deliberately small budget — and an honest test of whether it survives.
Fat FIRE
A no-compromise retirement, where contribution caps and tax become the binding constraint.
Drawdown / SWR
Thousands of simulated market paths to test whether your withdrawal rate survives.