Coast FIRE at 40
Coast FIRE at 40: with $40,000 of planned retirement spending, a 4% withdrawal rate and a 5% real return, you need about $295,303 invested today for compounding alone to reach the $1,000,000 target by 65 — no further contributions required. At 40 the runway is 25 years and $1 becomes about $3.39 by 65 at a 5% real return; the coast number is now about 30% of the full target. Peak earning years are usually just ahead, which cuts both ways: contributions can be large, but so can the spending baseline — and the expense input, not the return assumption, is what most often pushes a 40-year-old's coast number out of reach.
Coast FIRE at 40 reference last updated · reference source
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What this tool does
Coast FIRE at 40: with $40,000 of planned retirement spending, a 4% withdrawal rate and a 5% real return, you need about $295,303 invested today for compounding alone to reach the $1,000,000 target by 65 — no further contributions required. At 40 the runway is 25 years and $1 becomes about $3.39 by 65 at a 5% real return; the coast number is now about 30% of the full target. Peak earning years are usually just ahead, which cuts both ways: contributions can be large, but so can the spending baseline — and the expense input, not the return assumption, is what most often pushes a 40-year-old's coast number out of reach.
How to use the Coast FIRE at 40
- Check Current age: 40.
- Review the Coast FIRE at 40 result and its exact-value comparison table.
- Verify assumptions before applying the result.
Formula
retirement target=expenses/(SWR/100); coast target=retirement target/(1+return/100)^(retirement age−current age)
- expenses
- Annual retirement expenses
- swr
- Withdrawal rate (%)
- age
- Current age
- retire
- Retirement age
- return
- Annual real return (%)
Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Use inflation-adjusted expenses and real returns for constant purchasing power.
Worked example
Coast FIRE at 40: Current age = 40. Coast FIRE at 40: with $40,000 of planned retirement spending, a 4% withdrawal rate and a 5% real return, you need about $295,303 invested today for compounding alone to reach the $1,000,000 target by 65 — no further contributions required. At 40 the runway is 25 years and $1 becomes about $3.39 by 65 at a 5% real return; the coast number is now about 30% of the full target. Peak earning years are usually just ahead, which cuts both ways: contributions can be large, but so can the spending baseline — and the expense input, not the return assumption, is what most often pushes a 40-year-old's coast number out of reach.
Inputs
- Annual retirement expenses40000
- Withdrawal rate (%)4
- Current age40
- Retirement age65
- Annual real return (%)5
Result
- Coast FIRE balance needed now$295,302.77
- Retirement portfolio target$1,000,000.00
- Years for compound growth25
- Growth multiple by age 653.39
- Coast number as a share of the full target29.5%
Coast FIRE numbers at age 40 (4% withdrawal rate, 5% real return, retire at 65)
| Annual retirement spending | Coast FIRE number at 40 | Full target at 65 |
|---|---|---|
| 30000 | 221477 | 750000 |
| 40000 | 295303 | 1000000 |
| 50000 | 369128 | 1250000 |
| 60000 | 442954 | 1500000 |
| 80000 | 590606 | 2000000 |
Results explained
- Coast FIRE balance needed now
- Full retirement target discounted by 25 years of compound growth at the stated real return, for a 40-year-old.
- Retirement portfolio target
- Annual retirement expenses divided by the withdrawal rate (the 25× rule at a 4% rate).
- Growth multiple by age 65
- What $1 invested at this age becomes by retirement at the stated return, before any further contributions.
- Coast number as a share of the full target
- How much of the eventual portfolio must already exist today; the rest is expected from compounding.
Frequently asked questions
About $295,303 under the default assumptions ($40,000 annual retirement spending, 4% withdrawal rate, 5% real return, retirement at 65). The reference table shows the number for other spending levels at exactly this age.
Reaching age 45 before hitting the number raises the required balance from about $295,303 to about $376,889 — roughly $81,587 more — because five years of compounding are gone. The gap is the true price of delay, and it widens with every age step.
Use peak-income years deliberately: direct bonuses and raises to the portfolio until the coast line is crossed, then any career downshift (part-time, lower-paid but preferred work) stops being a retirement risk. Keep an eye on college and caring costs, which cluster in this decade and inflate the expense side.
It means the invested balance, left untouched, is projected to reach the retirement target by 65 under the stated return — it does not cover spending between now and then, and a decade of poor returns or higher retirement spending can un-coast the plan. Most people keep contributing at a lower rate as insurance.
Very: at a 4% real return the required balance at 40 is about $375,117, and at 6% it falls to about $232,999. That spread is why coast plans are usually built on conservative real returns, not best-case ones.
Through the expense input, not the asset side. If the mortgage will be paid off before retirement, retirement spending should exclude the payment — which can cut the target by a quarter or more — but then home equity still does not count as a coast asset. If you plan to carry a mortgage into retirement, keep the payment inside the $40,000-style expense figure you test on this page.