Coast FIRE number by age: how much you need at 25, 35, 45 and 55
One of the most common questions about Coast FIRE is simply: “How much should I have at my age?” There is no universal answer, because the result depends on how much you plan to spend, your withdrawal rate, when you want to retire and what return you assume. But a table built on a standard example shows the shape of the answer very clearly — and it shows why starting early matters so much. Every figure below was calculated with the same engine that powers our Coast FIRE calculator.
The assumptions behind the table
- FIRE number: $1,000,000 in today’s dollars. That corresponds to $40,000 of yearly spending at a 4% withdrawal rate, or $35,000 at 3.5%.
- Retirement age: 65.
- Returns: constant real (after-inflation) annual returns of 4%, 5%, 6% and 7%.
- Contributions: none after the coast point — that is the definition of coasting.
The formula is: Coast FIRE number = FIRE number ÷ (1 + real return)(65 − age).
Coast FIRE number for a $1 million target at 65
| Age now | Years to 65 | 4% real | 5% real | 6% real | 7% real |
|---|---|---|---|---|---|
| 25 | 40 | $208,289 | $142,046 | $97,222 | $66,780 |
| 30 | 35 | $253,415 | $181,290 | $130,105 | $93,663 |
| 35 | 30 | $308,319 | $231,377 | $174,110 | $131,367 |
| 40 | 25 | $375,117 | $295,303 | $232,999 | $184,249 |
| 45 | 20 | $456,387 | $376,889 | $311,805 | $258,419 |
| 50 | 15 | $555,265 | $481,017 | $417,265 | $362,446 |
| 55 | 10 | $675,564 | $613,913 | $558,395 | $508,349 |
Rounded to the nearest dollar. These are arithmetic illustrations, not targets anyone should treat as guaranteed.
Scaling the table to your own FIRE number
Because the formula is linear in the FIRE number, you can scale the table. Work out your FIRE number with the FIRE number calculator, divide it by one million, and multiply the table entry by that factor.
For example, if you plan to spend $60,000 a year with no other income and use a 4% rate, your FIRE number is $1,500,000 — a factor of 1.5. At age 40 and a 5% real return, your Coast FIRE number is about $295,303 × 1.5 ≈ $442,955. If you expect $18,000 a year of Social Security in today’s dollars from your retirement age, the portfolio only needs to cover $42,000, the FIRE number becomes $1,050,000, and the factor is 1.05.
If you want to retire earlier than 65, use the row for an age that leaves the same number of years. Someone who is 30 and wants to retire at 55 has 25 years, the same as the age-40 row.
What the table teaches
Time is the biggest lever. At a 5% real return, a 25-year-old needs about $142,000 to coast to $1 million; a 45-year-old needs about $377,000. Each extra decade of compounding cuts the requirement by roughly 39% at 5% real, because 1.0510 ≈ 1.63.
The return assumption is the second-biggest lever. For a 25-year-old the difference between 4% and 7% real is more than threefold. That is why it is sensible to test a range rather than pick the most optimistic number. A useful habit is to plan on a conservative return and treat anything better as a bonus.
Late starters are not out of the game. The Coast FIRE requirement rises with age, but so do typical incomes and savings capacity, and catch-up contribution limits for workers aged 50 and over give extra tax-advantaged room. The IRS sets an $8,000 catch-up for 401(k) participants aged 50 and over in 2026, and $11,250 for ages 60 to 63 where the plan allows. See our contribution limits guide.
How this compares with “net worth by age” figures
You will often see median or average net worth by age quoted from the Federal Reserve’s Survey of Consumer Finances. Those figures measure total household net worth — including home equity and other assets — and describe what households actually have, not what anyone needs. They are a different question from the Coast FIRE number, which is about investable retirement assets measured against your own spending. Comparing yourself with a national median tells you little about whether your plan works; comparing your invested balance with your own Coast FIRE number tells you much more.
Which money counts?
Count assets you intend to use for retirement and that can grow: 401(k), 403(b), 457, IRA and Roth IRA balances, HSA investments if you plan to use them in retirement, and taxable brokerage accounts earmarked for retirement. Do not count your emergency fund, money for a home purchase, or your home itself unless you genuinely plan to sell or downsize to fund retirement.
Be careful with pre-tax accounts. A dollar in a traditional 401(k) is not a dollar of spending, because withdrawals are generally taxed. Either include expected taxes in your spending figure or discount pre-tax balances.
Checking your position
- Find your FIRE number using realistic spending.
- Pick your target retirement age and count the years.
- Look up or calculate your Coast FIRE number at three returns.
- Compare with your invested retirement assets today.
- If you are short, use the calculator’s monthly contribution field to see when you would reach it.
A worked comparison: two savers, same target
Consider two people who each want $40,000 a year at 65 with a 4% withdrawal rate. Jordan invests $142,000 by age 25 and then contributes nothing more. Sam starts later and needs about $377,000 invested at 45 to coast to the same target. At a 5% real return both would, in this model, reach roughly $1,000,000 in today’s dollars at 65. Jordan’s advantage is not a smarter portfolio; it is twenty extra years of compounding. Sam is not doomed either: a 45-year-old earning more and saving aggressively can close a gap faster than a 25-year-old on an entry-level salary. The point of the table is to show what each year is worth, not to rank people.
Using the table as a yearly checkpoint
A practical routine is to note your invested retirement balance once a year, on the same date, and compare it with your row at a conservative return. If you are ahead, you can consider easing off contributions or changing work. If a bad year put you behind, the table shows how much more you would need — and the calculator’s monthly field shows how long it would take to catch up. Keeping a simple log of these yearly checks also helps you see whether your spending estimate is drifting.
Caveats
The table assumes the same return every year, which no market delivers. Sequence-of-returns risk, inflation surprises, taxes, fees and changes in spending can all move the outcome. Rechecking each year with your real balance turns the table from a guess into a feedback loop. Nothing here is investment advice.