Free Coast FIRE calculator
How do you calculate your Coast FIRE number?
Run the numbers here. Afterward, save your goal and log progress so you’re not starting from a blank form next time.
Coast FIRE calculator
Free — find your Coast FIRE number, then track progress.
Today's dollars
401(k), IRA, brokerage — exclude home equity
Set to 0 to test if you've already hit Coast FIRE
Assumptions
Coast FIRE number
$355,528
You need $285,528 more to coast (20% funded).
FIRE number
$1,250,000
Years to coast
14 yrs
You have
$70,000
Real return
3.88%
Projected value
$3M
Monthly spending
$10,055
Today's value
$3,741
Why track Coast FIRE progress after the calculator?
Start with Coast FIRE numbers, then keep Actual vs Goal honest as balances change.
Coast FIRE in one pass
Age, spending target, portfolio, and assumptions in — Coast threshold, FIRE target, and years remaining out.
Growth vs contributions, side by side
Model what happens if you keep investing — or pause contributions and let returns carry the plan.
What-if without rewriting everything
Nudge retirement age, withdrawal rate, or return assumptions and immediately see how your gap moves.
Portfolio that matches real accounts
Keep 401(k), IRA, Roth, brokerage, HSA, and the rest labeled so syncing into your FIRE progress stays accurate.
Actual path next to the goal line
Watch projected growth against the Coast line by age — useful when you're asking “am I on track?” not just “what's the formula?”
History you can return to
Optional account: save the goal, log portfolio updates, and revisit the same plan instead of starting from a blank form.
Coast FIRE basics
What is Coast FIRE, and how is it different from FIRE?
Coast FIRE means your invested nest egg is already large enough that, with no further retirement contributions, expected market growth can still reach your full FIRE number by your chosen retirement age. You usually still need earned income for day-to-day spending until you actually retire.
| Milestone | What it means | Still need a paycheck? |
|---|---|---|
| Coast FIRE | Portfolio can compound to your FIRE nest egg by target age with $0 more retirement contributions. | Yes — for living costs until retirement |
| Full FIRE | Nest egg is large enough that a sustainable withdrawal rate covers planned spending. | No — optional work only |
Which balances belong in a Coast FIRE calculator?
Most Coast FIRE plans count invested retirement and brokerage money — not every dollar of net worth.
- 401(k), 403(b), and similar workplace plans
- Traditional IRA and Roth IRA
- Taxable brokerage accounts invested for the long term
- Invested HSA balances (when used as a retirement vehicle)
Typically exclude primary-home equity and cash reserved for near-term spending.
What assumptions does WorthCay use by default?
- Expected return: ~7% nominal as a neutral starting point for a diversified stock-heavy portfolio (stress-test lower).
- Inflation: ~3% — real return ≈ nominal return minus inflation.
- Safe withdrawal rate (SWR): 4% when converting spending into a full FIRE number (FIRE ≈ annual spending ÷ 0.04).
“A withdrawal rate is considered safe if portfolio failure is unlikely over a multi-decade retirement; the often-cited 4% rule comes from historical U.S. market research such as the Trinity study and related safe-withdrawal-rate work.”
By WorthCay Team · ·
What should you know before using a Coast FIRE calculator?
How WorthCay thinks about Coast FIRE, inputs, and what stays free.
What does WorthCay mean by “Worth”?
- Your Worth is the independence target and the gap from where you are now — Coast threshold, full FIRE number, and how far your portfolio still has to go.
What is Coast FIRE in plain terms?
- You've built a large enough invested nest egg that, with no further retirement contributions, market growth can still get you to your planned nest egg by the age you choose. Day-to-day living costs still need income until you actually retire.
How is this different from a spreadsheet one-liner?
- The public calculator answers “what's my Coast number?” in one sitting. After that, WorthCay is built so you can save the plan and compare Actual vs Goal as balances change — not re-enter everything every quarter.
Which balances belong in the portfolio total?
- Invested retirement and brokerage money: 401(k), IRA, Roth, taxable brokerage, invested HSA, and similar. Most people leave out primary-home equity and cash earmarked for near-term spending.
How should I treat return and inflation assumptions?
- Defaults are a neutral starting point. Stress-test with lower real returns and higher inflation — if the plan only works on rosy numbers, treat the Coast date as aspirational.
Is signup required?
- No. Anyone can run the calculator. Sign up when you want the goal and progress history stored so next visit isn't a blank form.