Future Purchasing Power

Estimate how much today's money will really be worth years from now, and how quickly inflation can halve it.

Project your money's real value

Amount today (USD)

Assumed annual inflation (% per year)

Years

Please enter a valid amount, inflation rate, and number of years.

Purchasing power lost

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Erosion factor

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Rule of 70

Divide 70 by an annual rate to estimate doubling or halving time.

Money doubles in

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Purchasing power halves in

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Rule of 70: at a steady 3% rate, prices double (and buying power halves) roughly every 23.3 years.

Understanding the projection

This tool applies a constant annual inflation rate to see how your money's buying power shrinks. It is a what-if scenario, not a prediction — real inflation varies year to year.

The formula divides your amount by (1 + rate)^years. At 3% for 30 years, that divisor is about 2.43, so $1,000 today buys what roughly $412 would buy today after three decades of steady 3% inflation. The purchasing power lost — about 59% — is the share of your money's real value that inflation would consume.

The rule of 70 is a shortcut: 70 divided by the annual percentage rate approximates the years to double (for growth) or halve (for inflation). At 3%, that is about 23.3 years. It works because of how compound growth behaves and is accurate for rates roughly between 1% and 10%. For more on the math behind compounding, try the inflation-rate calculator.