Money

Inflation Calculator

Enter your amount, annual inflation rate, and time period to simulate the erosion of purchasing power. Useful for retirement planning and long-term savings analysis.


Current Amount
Annual Inflation Rate
%
Years
yr
Real Purchasing Power
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Purchasing Power Lost
−{{ fmt(result.lossAmount) }}
Purchasing Power Loss Rate
−{{ fmtRate(result.lossRate) }}%
Real Purchasing Power: {{ (result.realValue / amount * 100).toFixed(0) }}% Purchasing Power Lost: {{ (result.lossAmount / amount * 100).toFixed(0) }}%
Year Real Value Nominal Needed
{{ row.year }} {{ fmt(row.realValue) }} {{ fmt(row.nominalNeeded) }}

Real Value of 1,000,000 by Inflation Rate

Real purchasing power of 1,000,000 units after various years and inflation rates.

Period \ Rate 1% 2% 3% 5%
1yr 990,099 980,392 970,874 952,381
5yr 951,466 905,731 862,609 783,526
10yr 905,287 820,348 744,094 613,913
20yr 819,544 672,971 553,676 376,889
30yr 741,923 552,071 411,987 231,377

Tips

  • Central banks typically target an inflation rate of around 2% per year. At this rate, purchasing power halves in about 36 years (Rule of 72: 72 ÷ 2 = 36).
  • Rule of 72: divide 72 by the annual inflation rate to estimate how many years it takes for purchasing power to halve. At 3%, that's about 24 years; at 5%, about 14 years.
  • When evaluating investments, focus on real returns (nominal return minus inflation). A 5% return with 3% inflation yields only about 2% in real terms.
  • Cash and savings accounts preserve nominal value but lose real purchasing power during inflationary periods.

FAQ

Check your country's statistics bureau for the Consumer Price Index (CPI). In Japan, the Ministry of Internal Affairs publishes monthly CPI data. The Bank of Japan targets 2% annual inflation.

Rather than a nominal amount, real purchasing power measures what you can actually buy with your money, expressed in today's value. As inflation rises, the same nominal amount buys less.

Diversifying into inflation-resistant assets such as equities, real estate, and inflation-linked bonds is a common strategy. Holding only cash exposes you to inflation risk. This tool provides estimates only — consult a financial advisor for investment decisions.
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Side Note — Hyperinflation and the History of Money

Post-war Japan (1945–1948) experienced hyperinflation exceeding 100–500% annually. What cost ¥100 in 1945 cost over 100 times as much by 1949. The Dodge Line fiscal austerity and Korean War demand eventually brought prices under control.

The opposite problem — deflation — plagued Japan for decades starting in the late 1990s. Falling prices caused consumers to delay purchases, creating a deflationary spiral that stunted economic growth. Both extremes cause significant economic damage when left unchecked.