投資與複利

輸入下方數值,立即取得複利成長、退休儲蓄目標、實質報酬率試算結果。

%

台股長期約 7–9%、全球股市 6–8%

最終資產
$5,613,140
累積投入
$2,500,000
複利收益
$3,113,140

資產成長曲線

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Inflation-Adjusted Real Return Calculator

A nominal 7% isn't really 7%. Deduct inflation to see your true return.

What this calculator does

Financial news often quotes a 'nominal return rate' (like an 8% annual gain), which ignores inflation. If inflation runs at 3% during that same period, your actual purchasing power only went up by 4.85%. This calculator uses the Fisher equation to accurately calculate real returns, helping you realistically gauge true wealth accumulation. Long-term retirement planning heavily relies on real returns—using nominal returns for 30-year projections usually results in a severe shortfall in actual buying power.

Formula & how it works

Fisher Equation: (1 + Nominal Rate) = (1 + Real Rate) × (1 + Inflation Rate). Real Rate = ( (1 + Nominal) / (1 + Inflation) ) − 1.

Worked examples

  • Nominal 7%, Inflation 3%: The real return is roughly 3.88%. Over 30 years, an initial 1M grows to a real purchasing power of 3.13M (not 7.61M as nominal math suggests).
  • During the 1970s, the US stock market gained a nominal 6% annually, but with inflation at 7%, real returns were negative—this is what investors call a 'lost decade'.

Frequently asked questions

Can't I just subtract inflation from the nominal return?
Simple subtraction is an approximation, but it loses accuracy when inflation is high. For example, 10% nominal minus 6% inflation implies 4%, but the true real return is 3.77%.
Which inflation rate should I use?
Refer to the CPI (Consumer Price Index) in your country. Historically, a 2% to 3% estimate is standard for long-term calculations.