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.
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| Annual Inflation Rate |
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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 |
What Is an Inflation Calculator?
An inflation calculator works out how much real purchasing power a sum of money today will still hold in the future, based on an assumed annual inflation rate and a time horizon. When prices keep rising, the same amount of money buys less every year. Putting that erosion into figures and a chart gives you something concrete to work from when you plan long-term savings or a life plan.
Keep in mind that this is a simulation which assumes the annual rate you enter holds steady for the whole period. Real inflation varies from year to year, so it is worth running several scenarios — 1%, 2% and 3% a year, for instance — and treating the result as a range rather than a single number.
How to Use the Inflation Calculator
- Enter the amount you hold today Type in the principal whose future purchasing power you want to know, such as cash or a bank balance.
- Enter the annual inflation rate you want to assume Enter the rate you want to model — for example 2% a year, the Bank of Japan's target.
- Enter the time horizon Enter, in years, how far into the future you want the purchasing power calculated.
- Check the result and the chart The real purchasing power, the amount lost and the percentage decline appear together, with a year-by-year table and chart showing how the value moves.
Tips for getting more out of it
- 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.
When an Inflation Calculation Comes in Handy
Revisiting your retirement savings target
The longer you have until retirement, the greater the effect of inflation, so you can size your retirement fund by real purchasing power rather than by the nominal target alone.
Seeing the risk in cash and deposits
Put a concrete figure on how much real value cash or a near-zero-interest deposit loses under inflation.
Setting a target return for investments
Since assets shrink in real terms unless returns beat inflation, this gives you a basis for deciding the target return in an investment plan.
Checking the real change in your pay
If a pay rise falls short of inflation, your income has fallen in real terms. This helps you look past the nominal increase to the change in real value.
Inflation Terms Explained
- Real Purchasing Power
- Not the nominal figure, but what that money can actually buy, expressed in today's value. The further inflation runs, the lower the real purchasing power of the same nominal amount.
- Nominal Amount
- The figure exactly as shown, with no adjustment for price changes. It is the counterpart to real purchasing power.
- Rule of 72
- A rule of thumb that estimates the years for assets or prices to double — or halve — as 72 divided by the annual rate. At 2% a year, purchasing power halves in roughly 36 years.
- Real Return
- The nominal return on an investment minus the inflation rate, that is, the real growth of your assets. A high nominal return still leaves a small real return if inflation is high.
- Consumer Price Index (CPI)
- An index of price movements for the goods and services households buy, published monthly by Japan's Statistics Bureau. It is the figure most widely cited as the actual inflation rate.
FAQ
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.