Set the destination
Yearly retirement spending divided by your withdrawal rate gives the FIRE number. At a 4% rate, every dollar of yearly spending needs twenty five dollars of portfolio behind it.
Financial independence
Coast FIRE calculator
Find the balance that could reach your retirement number on growth alone, with nothing added after today, and see how far your invested money is from it right now.
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Your scenario
Build a coast scenario
How the two numbers differ
The coast number ignores your monthly contribution on purpose: it answers what today's balance can do by itself. The projected balance in the results keeps contributing until retirement, so you can compare the two paths.
The coast line
Your coast number age by age
The coast number rises every year, because each year leaves less time for compounding to do the work. Your projected balance rises too. Where the balance crosses the coast number is the age this scenario says you could stop contributing.
| Age | Coast number | Projected balance | On track |
|---|---|---|---|
| 30 | $130,365.04 | $25,000.00 | Not yet |
| 31 | $139,789.14 | $33,003.53 | Not yet |
| 32 | $149,894.51 | $41,585.66 | Not yet |
| 33 | $160,730.40 | $50,788.18 | Not yet |
| 34 | $172,349.61 | $60,655.94 | Not yet |
| 35 | $184,808.78 | $71,237.06 | Not yet |
| 36 | $198,168.62 | $82,583.09 | Not yet |
| 37 | $212,494.25 | $94,749.31 | Not yet |
| 38 | $227,855.47 | $107,795.04 | Not yet |
| 39 | $244,327.16 | $121,783.83 | Not yet |
| 40 | $261,989.60 | $136,783.90 | Not yet |
| 41 | $280,928.84 | $152,868.33 | Not yet |
| 42 | $301,237.21 | $170,115.50 | Not yet |
| 43 | $323,013.68 | $188,609.45 | Not yet |
| 44 | $346,364.36 | $208,440.34 | Not yet |
| 45 | $371,403.07 | $229,704.81 | Not yet |
| 46 | $398,251.83 | $252,506.47 | Not yet |
| 47 | $427,041.48 | $276,956.45 | Not yet |
| 48 | $457,912.35 | $303,173.95 | Not yet |
| 49 | $491,014.87 | $331,286.72 | Not yet |
| 50 | $526,510.37 | $361,431.76 | Not yet |
| 51 | $564,571.85 | $393,755.98 | Not yet |
| 52 | $605,384.79 | $428,416.93 | Not yet |
| 53 | $649,148.11 | $465,583.52 | Not yet |
| 54 | $696,075.08 | $505,436.86 | Not yet |
| 55 | $746,394.40 | $548,171.22 | Not yet |
| 56 | $800,351.31 | $593,994.86 | Not yet |
| 57 | $858,208.77 | $643,131.07 | Not yet |
| 58 | $920,248.76 | $695,819.36 | Not yet |
| 59 | $986,773.61 | $752,316.49 | Not yet |
| 60 | $1,058,107.56 | $812,897.80 | Not yet |
| 61 | $1,134,598.24 | $877,858.53 | Not yet |
| 62 | $1,216,618.44 | $947,515.30 | Not yet |
| 63 | $1,304,567.88 | $1,022,207.53 | Not yet |
| 64 | $1,398,875.20 | $1,102,299.29 | Not yet |
| 65 | $1,500,000.00 | $1,188,180.88 | Not yet |
Start here
What Coast FIRE actually means
FIRE stands for financial independence, retire early. The idea behind it is simple even if the arithmetic is not: build a pot of invested money large enough that what it produces can cover your living costs, so working becomes a choice rather than a requirement. The size of that pot is usually called a FIRE number, and it comes from two things you decide yourself: how much you expect to spend in a year, and what share of the portfolio you are willing to withdraw to fund that spending.
Coast FIRE is a smaller, earlier milestone on the same road. You reach it when the money already invested is large enough to grow into your FIRE number by your retirement age without a single further contribution. From that point the pot can look after itself. You still work, you still pay for the years between now and retirement out of income, but the retirement account no longer depends on you feeding it.
That is why the coast number is smaller than the FIRE number, often much smaller. It is the same target seen from further away: the FIRE number discounted back through every month of compounding between today and the age you chose. The longer the runway, the smaller the amount that has to be sitting there now.
Discount it back
Run the expected return backwards from retirement to today. What comes out is the balance that would arrive at the FIRE number on growth alone, which is the coast number.
Compare it with today
If your invested balance is already above that line, the scenario says you are coasting. If it is below, the gap is what this model says still has to go in.
Terms worth knowing
- FIRE
- Financial independence, retire early. A shorthand for having enough invested that work becomes optional, whenever that happens.
- FIRE number
- The portfolio balance that supports your yearly spending at your chosen withdrawal rate. Spending divided by that rate.
- Coast FIRE
- Having enough invested today that it can reach your FIRE number by retirement on growth alone, without another contribution.
- Withdrawal rate
- The share of a portfolio taken out in the first year of retirement, often adjusted for inflation each year after.
- Nominal return
- A return before inflation is removed. A real return is what is left after inflation, and it is the one that buys groceries.
- Sequence risk
- The risk that poor returns arrive early in retirement, when withdrawals are taken from a shrinking balance and cannot be undone.
Four assumptions
The inputs that move the answer
Every figure on this page rests on four assumptions you typed in. None of them are facts about the future. Knowing which one your result leans on hardest is more useful than the result itself.
Yearly spending in retirement
This is the biggest lever and the hardest to guess decades ahead. Housing costs, health care, family, and where you live can all move it. If you are unsure, run a lean figure and a comfortable one and treat the answer as a band rather than a point.
Withdrawal rate
The withdrawal rate converts spending into a portfolio size. A lower rate is a more cautious plan and a larger number. The often quoted 4% figure came from historical United States data over 30-year retirements and carries assumptions that may not match yours.
Expected annual return
Because it compounds across every month, small changes here move the coast number a lot. Decide whether you are using a nominal return or a return with inflation already removed, then keep the spending figure in the same terms.
The two ages
The gap between your current age and your retirement age is the runway. Moving retirement one year later gives compounding another twelve months and lowers the coast number. Moving it earlier raises the coast number sharply.
Use a range
A scenario, not a prediction
This calculator draws one smooth line from today to retirement. Markets do not move in smooth lines, and a plan built on a single tidy path can break in ways the path never shows. Test a few versions, and read the list of what is missing before you lean on any of them.
Scenarios worth testing
- A lower return. Rerun the same inputs a point or two below your first guess and see how far the coast number moves.
- A lower withdrawal rate. A more cautious rate raises the FIRE number and the coast number with it.
- Higher retirement spending. Health care and housing can rise faster than a general inflation figure.
- An earlier retirement age. Cutting the runway is the fastest way to see how much of this rests on time.
What this model leaves out
- Inflation. Nothing here is adjusted for it. Keep your return and your spending in the same terms, either both nominal or both real.
- Sequence of returns. The same average can end very differently depending on when the bad years land, especially once withdrawals begin.
- Taxes, fees, and account rules. All of them reduce what reaches you, and they differ by account type and country.
- Changing spending. Retirement spending is held constant here, though real spending tends to move through retirement rather than sit still.
- Other income. Social Security, pensions, rental income, and part-time work all reduce what the portfolio has to carry, and none of them appear in this math.
Common questions
Coast FIRE calculator FAQ
What is Coast FIRE?
Coast FIRE is the point where the money you have already invested is large enough to reach your retirement target on its own, purely through compounding, by the age you picked. You still work and still pay your bills, but you no longer have to add to the retirement pot for it to arrive on time. It is a milestone on the way to full financial independence, not a retirement date.
How is the coast number calculated?
Two steps. First the calculator turns your yearly retirement spending into a FIRE number by dividing it by your withdrawal rate. Then it discounts that FIRE number back from your retirement age to today at the expected return, compounded monthly. The result is the balance that grows into the FIRE number over the years you have left, with nothing added.
What withdrawal rate should I use?
That is your call, and this calculator does not recommend one. The 4% figure comes from studies of historical United States market data over 30-year retirements, and it assumes a particular portfolio mix, annual inflation adjustments, and a fixed retirement length. A longer retirement, different assets, higher fees, or different market history can all point to a different number. Try a range rather than one rate.
Should the expected return be before or after inflation?
Be consistent, because this calculator does not adjust for inflation anywhere. If you enter a nominal return, then your spending figure and the resulting FIRE number are in future dollars too, and they will buy less than the same amount buys today. If you enter a real return, one with inflation already removed, then the figures stay in today's buying power. Mixing the two overstates the result.
What happens if I keep contributing after I hit the coast number?
You reach the FIRE number earlier, or you reach a bigger number at the same age. Nothing about coasting requires you to stop. The projected balance at retirement in the results keeps your monthly contribution running the whole way, so you can see both stories side by side: what growth alone delivers, and what growth plus contributions delivers.
Why does a small change in the return rate move the coast number so much?
Because the return is compounded over every month between now and retirement, and the coast number is that compounding run in reverse. Over 35 years, one extra percentage point can cut the balance you need today by roughly a third. That sensitivity is exactly why a single optimistic rate makes a fragile plan and a range of rates makes a sturdier one.
Does this calculator account for taxes?
No. Taxes are left out entirely, on both the growing balance and the withdrawals. A traditional 401(k), a Roth IRA, and a taxable brokerage account with identical balances do not produce identical spending money, because the tax due, the timing of it, and the rules about early access all differ. Account type can change the size of the pot you actually need.
Is hitting the coast number the same as being able to stop working?
No. Coasting means the retirement pot can look after itself. Everything between now and retirement still has to be paid for out of income: rent or mortgage, food, insurance, childcare, and any emergency that arrives. Many people use the milestone to move to lower paid work they prefer, cut hours, or redirect savings toward a nearer goal, not to stop earning.
The coast FIRE formula
F = S ÷ w C = F ÷ (1 + r)n
F is the FIRE number, S is yearly spending in retirement, and w is the withdrawal rate as a decimal. C is the coast number, r is the monthly return (the annual rate divided by 12), and n is the number of months to retirement. Running C forward for those same n months returns F, which is what makes it a coast number.
- Monthly compounding
- Age-by-age coast line
- Contributions kept separate
This calculator provides an estimate for education and planning. It is not financial, investment, tax, or legal advice, and it does not predict or guarantee returns. Investments can lose value. The scenario assumes a fixed return, a fixed monthly contribution, and constant retirement spending, and it excludes inflation, taxes, fees, account rules, and any other source of retirement income. Consider a qualified professional for guidance about your situation.
Keep the plan moving
The coast number only means something if you know what is actually invested.
Track investments, cash, spending, and net worth together in Pocketwatch.