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Inflation-Adjusted Purchasing Power Calculator

See how inflation reduces the real value of money over time and what a fixed sum will actually buy in the future.

Inputs

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What is this fixed sum worth in today's dollars?

Results update as you type, and the address bar keeps your numbers so the link you share reopens this exact calculation.

Future equivalent of today's amount

$18,061

To match $10,000 of purchasing power today.

Detailed results
Purchasing power lost to inflation$8,061
Percent of purchasing power lost44.6%
Real value of fixed future amount (today's $)$5,537
Years until purchasing power halves23.4

What this result means

Future equivalent of today's amount: $18,061.

You'll need $18,061 in the future to match today's purchasing power — inflation erodes 44.6% of your money's real value. Your fixed future amount is worth $5,537 in today's dollars.

Purchasing Power Erosion Over Time

Year-by-year real value of today's dollar amount.

Purchasing Power Erosion Over Time. 20 rows, first 12 shown.
YearFuture Equivalent ($)Real Purchasing Power (today's $)Purchasing Power Lost (%)
1$10,300$9,7092.9%
2$10,609$9,4265.7%
3$10,927$9,1518.5%
4$11,255$8,88511.2%
5$11,593$8,62613.7%
6$11,941$8,37516.3%
7$12,299$8,13118.7%
8$12,668$7,89421.1%
9$13,048$7,66423.4%
10$13,439$7,44125.6%
11$13,842$7,22427.8%
12$14,258$7,01429.9%

How this is calculated

Future equivalent = present × (1 + inflation)^years. Real value = future_amount / (1 + inflation)^years. Years to halve = ln(2) / ln(1 + inflation).

Inflation is the gradual increase in the general price level of goods and services. As prices rise, each dollar buys less — this loss of purchasing power is one of the most important forces in personal finance.

The rule of 72. Divide 72 by the inflation rate to estimate how many years it takes to halve purchasing power. At 3% inflation, your money loses half its purchasing power in roughly 24 years.

Why it matters for retirement. A $50,000 annual budget in today's dollars requires over $90,000 per year at 3% inflation after 20 years. Retirees on fixed incomes — pensions, annuities without cost-of-living adjustments — are especially vulnerable.

Real vs. nominal returns. Investment returns are often quoted in nominal terms. The real return is what remains after subtracting inflation. A 7% nominal return with 3% inflation yields approximately 4% in real purchasing power.

CPI vs. personal inflation. The Consumer Price Index (CPI) measures average inflation across a broad basket of goods. Your personal inflation rate may differ — healthcare and housing often inflate faster than CPI, while technology costs tend to deflate.

Assumptions

  • Inflation is applied at a constant annual rate (geometric compounding).
  • Purchasing power calculation uses the same rate for all goods and services.
  • Nominal figures are in current dollars; real figures converted to present-value dollars.
  • No tax effects modeled — applicable when comparing taxable investment returns against inflation.
  • Years-to-halve uses the exact logarithm formula, not the simplified Rule of 72.

Frequently asked questions

›What inflation rate should I use?

For general planning, the long-run US Consumer Price Index (CPI) average is roughly 3%. However, your personal inflation rate varies by spending patterns: healthcare and housing typically inflate faster at 5–7% annually, while technology goods often deflate. For retirement planning, use 2.5–3.5% as a baseline unless you expect concentrated spending in high-inflation categories. The trailing 10-year CPI average provides a recent anchoring point, but avoid anchoring only on the latest year if it was unusually high or low.

›How does inflation affect my investments?

Equities have historically delivered returns well above inflation over multi-decade periods, making them effective inflation hedges for long-term investors. Bonds and savings accounts often fail to keep pace during sustained high-inflation environments, eroding real purchasing power. Real assets—real estate, Treasury Inflation-Protected Securities (TIPS), and commodities—provide explicit inflation hedges. When comparing investment returns, always distinguish between nominal returns (headline numbers) and real returns (after inflation adjustment).

›What are TIPS?

TIPS (Treasury Inflation-Protected Securities) are U.S. government bonds whose principal adjusts upward each month based on the Consumer Price Index. If inflation rises, both your principal and interest payments increase proportionally, protecting your purchasing power. In exchange for this inflation protection, TIPS offer lower yields than regular Treasuries. They are especially useful for inflation-sensitive portions of a fixed-income portfolio or when you expect elevated future inflation but want government-backed safety.

›How does inflation affect Social Security?

Social Security benefits receive an annual Cost-of-Living Adjustment (COLA) tied to the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W), which means your monthly payment increases roughly in line with inflation. This automatic protection is a major advantage of Social Security over private savings. Private pensions and annuities that lack COLA riders steadily lose purchasing power: a pension paying $2,000 monthly today buys significantly less in 20 years if that payment never adjusts.

›Is deflation better than inflation?

No—deflation (declining prices) is often more damaging than inflation. Deflation creates perverse incentives: consumers delay purchases knowing items will cost less tomorrow, businesses cut investment and employment, and real debt burdens grow heavier because you repay loans with money worth more than when you borrowed. These dynamics can trigger deflationary spirals that suppress economic growth. Central banks worldwide target mild positive inflation—typically 2%—as a deliberate policy to avoid deflation and promote spending and investment.

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