老後資金計算ツール
The detailed guide below is currently available in English.
How this projection works
The projection tab works entirely in today’s dollars. Your income is grown to retirement age at your expected annual increase, converted to the share of income you want after retiring, then deflated back by inflation — so a 75% target under 3% raises and 3% inflation is simply 75% of today’s income. The required amount is the level withdrawal that gap supports from retirement until your life expectancy at the real (after-inflation) return, and your current savings plus yearly contributions are projected at the same real rate.
Reading the result
- A surplus means your current plan already funds the target; a shortfall comes with the extra monthly saving that closes it.
- The "Reach a Target Amount" tab skips the income questions: give it a goal and it tells you what to save monthly.
- The "Withdrawal" tab flips the view — given a nest egg, it reports how long inflation-adjusted monthly withdrawals last.
- Because the model assumes smooth returns, treat every figure as a planning yardstick rather than a guarantee.
よくある質問
Why does everything appear in today’s dollars?
Thinking in today’s dollars keeps results intuitive: a figure like $40,000 a year means what $40,000 buys now. The real return already strips out inflation, so no further adjustment is needed.
What return should I assume?
A balanced portfolio has historically returned roughly 5–8% nominal over long periods, but future returns are uncertain. Try a range — the difference between 6% and 8% over 30 years is enormous.
What percentage of my income will I need after retiring?
Common rules of thumb range from 70% to 85%: some spending drops (commuting, payroll taxes, saving itself) while healthcare often rises. Subtract dependable income such as Social Security in the "Other Income" field.