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FIRE calculator

How many years to retirement? Calculate target assets, time to FIRE, and retirement age using the 4% rule. Supports Coast FIRE mode with inflation and tax.

Inputs

ModeReach target
FIRE target
$900.0K
Monthly expense × 25 years
Time to FIRE
32.8yr
from today
FIRE age
62.8yo
currently 30 y/o
Expense at FIRE (nominal)
$6.7K
now $3.0K

Assets by age (today's value)

Real assetsFIRE target
Preset

How the FIRE calculator works

FIRE stands for 'Financial Independence, Retire Early.' This tool sets a target nest egg as a multiple of your annual spending, then stacks your monthly savings and after-tax returns onto your current assets, month by month, to simulate when you reach that target. Below we explain the 4% rule behind the target, a concrete numeric example, how taxes and inflation are handled for Korean residents, and Coast FIRE along with common mistakes.

The 4% rule and your target — why 25× annual spending

The money you need to retire is set by 'annual spending ÷ withdrawal rate.' This calculator computes target assets = monthly expense × 12 × (100 ÷ withdrawal rate), so a 4% withdrawal rate makes the target exactly 25× your annual spending. The intuition behind the 4% rule is that if you draw only 4% of your assets each year, the rest keeps growing in the market so the nest egg never runs dry. The reach date is found month by month: each month the balance earns (annual return ÷ 12), tax is deducted, and your monthly saving is added. Lowering the withdrawal rate to 3.5% raises the target to about 28.6×, which is more conservative; raising it to 5% lowers it to 20×, a more aggressive assumption.

Worked example — 2.5M monthly spend, 1.5M monthly saving, 7%

Spending 2.5 million KRW a month means 30 million a year, so the 4%-rule target is 750 million KRW. Starting from 50 million in current assets, saving 1.5 million a month, and compounding at 7% (assuming a 22% tax rate), savings drive growth early on, but as the balance swells there comes a point where returns overtake savings. After that crossover the curve steepens and you reach the target in roughly two decades. Raising your monthly saving to 2 million pulls the date forward by several years, while raising target spending to 3 million pushes the target to 900 million and delays it considerably. Monthly saving, return, and target spending are the three levers that decide your reach date.

Korean taxes and inflation — unified in real value

This calculator multiplies each month's gain by the tax rate you enter and deducts it. Interest and distributions from Korean savings and domestic ETFs are typically taxed at 15.4%, while overseas-ETF capital gains face 22% (with a 2.5M KRW annual deduction), so adjust the rate to match your product. For tax-advantaged accounts like ISA or pension savings, you can lower the rate to compare. All asset figures are unified in today's money (real value) — 750 million shown 30 years out means 'the same purchasing power as 750 million today.' Internally the tool inflates the future nominal target by inflation to judge whether you've reached it, then converts back to today's terms for display. The actual nominal figure that will appear in your account is shown under 'monthly expense at FIRE (nominal).'

Coast FIRE and common mistakes

Coast FIRE is the state where assets you've already accumulated will, with no further saving, compound on their own into the target by your chosen retirement age. This calculator reverse-engineers that Coast threshold using after-tax, real returns up to your retirement age; once you reach it you no longer need to save and only need to cover living costs. The first common mistake is entering an unrealistic return — real returns after inflation are usually 5–7%, so view a range across conservative, base, and optimistic scenarios. The second is trusting the 4% rule blindly — for Korean residents, 3.5% is a safer, more conservative figure given overseas-ETF taxes, currency risk, and low bond yields. Third, if you see 'not reached within 60 years,' it signals that your monthly saving is too low or target spending too high, so raise savings or cut spending (Lean FIRE) and run it again.

FAQ

How much money do I need to reach FIRE?

The core figure is 25× your annual spending. From the 4% rule (based on the Trinity Study, which found that withdrawing 4% of assets per year lasts 30+ years), target = annual spending ÷ 0.04 = annual spending × 25. ₩2.5M/month (₩30M/year) needs ₩750M; ₩4M/month (₩48M/year) needs ₩1.2B. A conservative 3.5% rate raises this to 28.6×; an aggressive 5% drops it to 20×.

What exactly is the 4% rule, and does it work in Korea?

From the 1998 Trinity University study: if you withdraw 4% of assets in year one and adjust withdrawals for inflation each year afterward, the probability of depleting your portfolio over 30 years is very low. But it's based on US stock/bond history, so Korean residents — facing FX risk, foreign-ETF capital gains tax (22%), and lower bond yields — often apply a conservative 3.3-3.5% instead.

How is Coast FIRE different from regular FIRE?

Coast FIRE is the point where you've saved enough that compounding alone, with zero additional saving, will carry you to your target by retirement age. Save a sufficient seed by 35, and even saving ₩0 afterward you'll hit the target at 65. While Standard FIRE means 'enough to quit today,' Coast FIRE means 'enough to ease off the savings accelerator' — reached far sooner. This calculator supports both modes.

What do Lean FIRE and Fat FIRE mean?

They classify retirement by lifestyle. Lean FIRE is a frugal retirement on under ~₩20M/year (target under ~₩500M); Fat FIRE is a comfortable retirement on ₩80M-100M+/year (target ₩2B+); Regular FIRE sits in between. Barista FIRE means working part-time to cover the gap. All use the same 4% rule — just change the monthly-expense input to see each type's required assets instantly.

Why is a 3.5% withdrawal rate safer?

A lower rate means you draw down a smaller share each year, so the principal lasts longer. The 4% figure assumes a 30-year retirement, but someone retiring in their 40s-50s faces a 40-60 year horizon, raising depletion risk. So earlier retirees are advised to use 3.25-3.5% (28-30× annual spending). Adjusting the withdrawal-rate input here shows how the target grows non-linearly as the rate falls.

How much faster do I reach FIRE if I already have assets?

Existing assets compound from day one, so the effect is large. For a ₩900M target with ₩300M current assets, ₩2M monthly saving, and 7% return, you may reach FIRE 8-10+ years sooner than starting from zero. Compounding accelerates over time, so a larger initial seed makes the final stretch — where 'assets grow on their own' — far more powerful.

Which matters more: monthly savings or return rate?

It depends on your time horizon. In the first 10 years, monthly savings (your savings rate) dominate, because small balances make compounding negligible. Over 20+ years, a 1-2pp difference in annual return can swing your final assets by hundreds of millions of won. Generally, the key to FIRE is a high savings rate (50%+ of income), while return strategy is to track the market via diversified index funds (S&P 500, total-world ETFs).

How does this calculator handle taxes?

Your input tax rate is applied to each month's investment gain (interest/appreciation) before compounding. For Korean residents, deposit/bond interest is generally taxed 15.4% (income 14% + local 1.4%), and foreign stock/ETF capital gains 22% (after a ₩2.5M annual deduction). Actual tax varies greatly by sale timing and account type (ISA/pension accounts reduce tax), so this is an estimate using a single average rate.

What's a realistic way to reach FIRE faster?

Mathematically, the most powerful lever for your FIRE date is your savings rate. A widely cited figure: saving 25% of income takes ~32 years, 50% takes ~17 years, and 65% takes ~10.5 years. So: ① cut spending to raise your savings rate, ② use tax-advantaged accounts (ISA, pension savings, IRP) to lower taxes, and ③ raise income via side work or promotion and funnel the increase into savings. Controlling spending acts more directly than raising income.

Can my assets keep growing even after retirement?

Yes. The 4% rule is conservative by design — historically, in many scenarios assets were larger after 30 years than at the start. When your real return (stocks' long-run real ~7%) exceeds the 4% withdrawal rate, the portfolio grows net even while you withdraw. The caveat is 'sequence of returns risk': a steep market drop in the first few years can shrink assets fast, so withdrawing conservatively early on is safer.

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This calculator is for informational purposes only. Actual tax and returns vary by individual circumstances and market conditions. Consult a tax advisor or financial professional for important decisions.