FIRE Calculator (VND)
FIRE stands for Financial Independence, Retire Early: the point at which your invested portfolio is large enough that withdrawals can cover your living costs indefinitely, so paid work becomes optional rather than mandatory. The whole movement reduces to one target — your FIRE number — equal to your annual spending divided by a safe withdrawal rate (SWR). Under the classic 4% rule, that is simply annual spending times 25.
If you are an expat living in Vietnam, your spending and portfolio are most naturally tracked in Vietnamese dong, even if you earn or invest partly abroad. Take the example loaded in the calculator: an annual budget of 600.000.000 VND (about 50M/month, a comfortable expat lifestyle) at a 4% withdrawal rate implies a FIRE number of 15.000.000.000 VND. Starting from 1.000.000.000 VND already invested and adding 40.000.000 VND/month, at an illustrative 7%/year return the portfolio reaches that target in 15 years.
Two levers dominate the outcome. The first is the withdrawal rate: lowering it from 4% to 3% — a common choice for people retiring very early with a 40-to-50-year horizon — raises the FIRE number from 15.000.000.000 to 20.000.000.000 VND and pushes the date out by 3 years. The second is your savings rate: the bigger your monthly contribution relative to spending, the sooner the date arrives. One caveat throughout: the return and withdrawal rates on this page are illustrative assumptions, not forecasts of any market.
How the calculator finds your number and timeline
Step 1 — The FIRE number (the 4% rule)
The FIRE number is the portfolio size from which you can draw a living without (statistically) running out:
FIRE# = Annual spending ÷ Safe withdrawal rate
| Symbol | Meaning |
|---|---|
| FIRE# | The FIRE number — target portfolio size |
| E | Annual living expenses |
| w | Safe withdrawal rate, e.g. 4% |
| NW₀ | Current investable net worth |
| C | Monthly investment contribution |
| r | Expected annual return |
With E = 600.000.000 VND and w = 4%: FIRE# = 600.000.000 ÷ 0.04 = 15.000.000.000 VND. The 4% rule comes from the Trinity Study, which found that withdrawing 4% of the starting portfolio (then adjusting for inflation each year) rarely exhausted a balanced portfolio over 30 years. A lower rate (3–3.5%) is safer for very long retirements but demands a bigger number.
Step 2 — Simulating the years to FIRE
The calculator runs a month-by-month projection over 40 years:
- Monthly return = r ÷ 12 (e.g. 7%/year becomes 0.583%/month).
- Each month: balance × (1 + monthly return), then add contribution C.
- Years to FIRE = the first year the start-of-year balance is ≥ FIRE#.
If the target is not reached within 40 years, the result shows "40+". The model deliberately omits taxes, inflation of your own spending, and market volatility — the balance grows smoothly at the assumed return. That is the key limitation: real returns are lumpy, so treat the year count as a planning estimate, not a fixed date.
Why the withdrawal rate matters so much
Because the FIRE number is inversely proportional to w. On the same 600.000.000 VND/year budget:
- w = 4% → FIRE# = 15.000.000.000 VND → 15 years
- w = 3% → FIRE# = 20.000.000.000 VND → 18 years
Choosing extra safety always costs extra accumulation years — there is no free lunch.
Worked example: 600.000.000 VND/year budget, 1.000.000.000 VND invested, 40.000.000 VND/month
Illustrative assumptions: a 7%/year return (compounded monthly), a 4% withdrawal rate, no taxes or inflation. Enter your own figures in the calculator above to personalise this.
FIRE number = 600.000.000 ÷ 0.04 = 15.000.000.000 VND. At that size, drawing 4%/year funds 600.000.000 VND of annual spending while (in theory) preserving capital.
| Milestone | Projected portfolio | Share of FIRE number |
|---|---|---|
| Today (year 0) | 1.000.000.000 | 7% |
| Year 5 | 4.281.341.326 | 29% |
| Year 10 | 8.933.053.674 | 60% |
| Year 15 | 15.527.438.600 | FIRE reached |
After 15 years the portfolio reaches 15.527.438.600 VND, clearing the 15.000.000.000 VND target around the year 2041. Over those 15 years you personally contributed only 8.200.000.000 VND (the 1.000.000.000 VND head start plus 15 × 12 × 40.000.000); the rest is compound growth.
Flexing one input
Hold everything else and drop the withdrawal rate to a more conservative 3%: the FIRE number jumps to 20.000.000.000 VND and the timeline stretches to 18 years. This is the single most important sensitivity in FIRE planning — and a reminder that the sequence of returns in your first decade of retirement (not just the average) is what the rule is really protecting against. If you want to know when you could stop contributing and simply let compounding carry you to the target, try FiMo's Coast FIRE calculator next.
Frequently asked questions
What is FIRE?
FIRE stands for Financial Independence, Retire Early. It is the point where your invested portfolio is large enough that withdrawals cover your living costs indefinitely, making paid work optional. The target is captured by your FIRE number = annual spending ÷ safe withdrawal rate. Under the 4% rule, the FIRE number equals 25 times your annual spending.
How do I calculate my FIRE number?
Divide your annual spending by your safe withdrawal rate. For a 600.000.000 VND/year budget at the 4% rule: FIRE# = 600.000.000 ÷ 0.04 = 15.000.000.000 VND. Choosing a more conservative 3% rate raises it to 20.000.000.000 VND. Enter your real expat budget in the calculator to get a personalised figure in VND.
Is the 4% rule reliable?
The 4% rule — withdraw 4% of the starting portfolio, then adjust for inflation each year — comes from the Trinity Study, which found a balanced portfolio rarely ran dry over 30 years. It is a solid starting point, not a guarantee. People retiring very early (40–50 year horizons) often prefer 3–3.5% for extra safety, accepting that a lower rate means a larger FIRE number and a longer accumulation phase.
How long until I reach FIRE?
It depends on your current portfolio, monthly contribution and return. In the example inputs (1.000.000.000 VND invested, 40.000.000 VND/month, an illustrative 7%/year return, a 15.000.000.000 VND target), the simulation reaches FIRE in 15 years — around the year 2041. Saving more each month or starting earlier shortens that timeline.
Does this FIRE calculator account for taxes and inflation?
No — the balance projection grows smoothly at the assumed return, with no taxes or inflation deducted, which keeps every figure easy to verify. To work in today's purchasing power, enter a real return (return minus inflation). Note the original 4% rule already builds in annual inflation adjustments to the withdrawal itself. Treat the year count as a planning estimate rather than a promise.
How is FIRE different from Coast FIRE?
Full FIRE means the portfolio is large enough to stop working entirely. Coast FIRE is an earlier milestone: you have saved enough that, even if you stop contributing and let compounding run, you will still hit your FIRE number by your target retirement age. Reaching Coast FIRE means you only need to earn enough to cover current expenses, not to keep saving. FiMo has a dedicated Coast FIRE calculator for that milestone.