What is this age checkpoint for?
In one sentence: This page shows the invested amount that could grow into your retirement target by age — so you can see whether you're ahead, on track, or behind under clear assumptions.
Why it matters: age changes how many years compound growth still has. The same retirement plan needs a smaller Coast number at 30 than at 45.
If you skip this check, it's easy to compare yourself to a full FIRE nest egg you don't need yet — or to feel behind without knowing whether the gap is five years of saving or a spending assumption.
Doing it right helps you:
- •See a Coast number for each age instead of guessing
- •Measure your gap against invested assets you already have
- •Feel what waiting costs when every other assumption stays the same
How does this benchmark work?
Two linked amounts: the full retirement target, then today's smaller Coast number.
The table discounts that target back to each age using real return and years left until retirement.
In plain steps:
- 1.Retirement target = annual expenses ÷ withdrawal rate
- 2.Coast FIRE number = retirement target ÷ (1 + real return)^years until retirement
All dollar figures are in today's purchasing power. 7% nominal return and 3% inflation produce a 3.9% real return. The 4% withdrawal rate used on this page is a planning assumption, not a promise that withdrawals will be sustainable.
What should you compare with the number?
Compare money you expect to leave invested for retirement — not every dollar you own.
Usually include
- •Retirement accounts such as a 401(k), IRA, or similar
- •Taxable brokerage investments set aside for retirement
Usually keep separate
- •Emergency cash and near-term spending reserves
- •Your primary home, unless your plan converts equity into retirement assets
- •Future income, pensions, and Social Security unless you model them on another page
What does an age-30 example look like?
More years left → a smaller Coast number for the same retirement plan.
At age 30, $40,000 of annual spending and a 4% withdrawal rate produce a $1,000,000 retirement target.
With 35 years until age 65 and a 3.9% real return, the Coast FIRE number is $263,555.
That Coast number is lower than the retirement target because the calculation assumes the invested amount keeps compounding until retirement.
Rule of thumb: more time to retirement lowers the Coast number when every other assumption stays the same.
What does this estimate not decide?
Use it as a planning checkpoint — not a green light to stop saving or quit your job.
The number does not decide:
- •Whether you can stop saving
- •Whether you can retire
- •Which investment mix to use
Taxes, fees, uneven returns, account-access rules, spending changes and life expectancy can all change the outcome.
Educational planning estimate, not personalized investment advice. Read the formula guide.
