Retirement Simulator (Asset Depletion Age)

Last updated: 2026-06-25

TL;DR

The retirement simulator grows your current assets by a monthly return while drawing down (monthly spending − monthly pension), and computes at what age your assets run out.

If the monthly growth exceeds the net withdrawal, your assets do not shrink and it shows sustainable. The result simplifies inflation and is a reference estimate.

Enter your retirement assets

KRW
Investable assets held at retirement.
yrs
Used to compute the depletion age (optional).
%
Using a real return (return − inflation) is conservative.
KRW
Monthly living costs after retirement.
KRW
Monthly pension such as the National Pension (optional). Blank = 0.

Market volatility, medical costs, taxes and inflation are simplified. This result is a reference estimate; run it conservatively several times.

How to use it

  1. Enter assets and age — your current retirement assets and your current age.
  2. Enter return, spending and pension — the expected annual return (%), monthly spending and monthly pension income.
  3. View the result — press Calculate to see how many years until your assets run out and at what age, in a table.

How the retirement simulation works

Assets in retirement are not idle — they keep being invested. This simulator repeats, each month, growing your assets by the monthly return (annual return ÷ 12) and then subtracting that month's net withdrawal (monthly spending − monthly pension). It finds the month assets hit 0 to compute the time and age until depletion.

Example duration by return rate, for 300M assets, 2.5M monthly spending and 0.8M pension (net withdrawal 1.7M)
Annual returnApprox. durationNote
0%about 14 years 9 monthsSimple drawdown, no growth
3%about 19 years 6 months
6.8% or morenever runs outMonthly growth ≥ net withdrawal

As the table shows, a higher return makes assets last longer, and above a certain level the principal does not shrink and lasts indefinitely. Raising your pension shrinks the net withdrawal for the same effect. That is why growing your monthly pension via the National Pension and pension savings is key. To first see the total fund you need, use the Retirement Fund Calculator.

Frequently asked questions (FAQ)

How does the retirement simulator calculate?

Month by month, it grows your assets by the monthly return (annual return ÷ 12), then subtracts the net withdrawal (monthly spending − monthly pension). It repeats until assets reach 0 to find the months and age until depletion. Inflation is not modeled separately for simplicity, so entering a real return rate is more conservative.

What does 'never runs out' mean?

If the monthly investment growth equals or exceeds the net withdrawal (spending − pension), the principal does not shrink and can last indefinitely, shown as 'never runs out (sustainable)'. The same result appears when your pension fully covers your spending, so you never need to dip into assets.

What return rate should I enter?

There is no single answer. A safe-asset focus might assume 2–3%, while a heavier stock weighting might assume 4–6%. After retirement, a conservative figure is safer, and entering a real return (nominal return − inflation) is more realistic.

Can I set my retirement date based on this result alone?

No. Market volatility, medical costs, taxes and longevity risk introduce many real-world variables, so this simulation is a reference estimate. Run it several times with conservative assumptions and decide alongside professional advice.

Last updated: 2026-06-25