Input the dollar amount you want to track.
Use historical CPI or a custom inflation rate.
Choose the years to compute purchasing power across.
See future or past purchasing power and loss percentage.
Inflation compounds against you the same way investment returns compound for you. At 3% annual inflation, prices double in about 24 years. At 5%, they double in 14 years. Knowing how much purchasing power you'll lose over time is essential for retirement planning, salary negotiation, and understanding the true return on your investments.
Future Value = Present Value × (1 + inflation)^years • Real Value = Nominal / (1 + inflation)^years
Long-run US inflation averages about 3% — but it's been much higher in some periods
Even modest inflation compounds dramatically over decades — 3% over 30 years roughly halves purchasing power
Cash savings lose purchasing power if interest rates don't keep up with inflation
Real return = Nominal return − Inflation (more precisely, Fisher equation)
Use category-specific inflation rates for healthcare, education — they run higher than CPI
Inflation-protected securities (TIPS) preserve purchasing power directly
Purchasing power measures the real value of money — how many goods and services a dollar can actually buy. Since 1913, when the Bureau of Labor Statistics began tracking the Consumer Price Index (CPI), the US dollar has lost over 96% of its purchasing power due to cumulative inflation. At an average annual inflation rate of about 3%, prices roughly double every 24 years, meaning $100 today will buy only about $50 worth of goods in 2050. This erosion affects everyone: retirees living on fixed income, workers negotiating salaries, investors comparing historical returns, and businesses setting long-term contracts. Purchasing power calculations are essential for converting historical dollar amounts into today's terms, projecting future costs for retirement planning, and evaluating whether investment returns truly outpace inflation. Central banks target a 2% annual inflation rate as healthy for economic growth, but actual inflation frequently deviates — reaching 9.1% in June 2022 in the US, for example. Understanding how inflation compounds over time is the first step toward protecting your financial future.
Purchasing power, not nominal dollars, is what determines your standard of living. A 4% raise during 6% inflation is actually a 2% pay cut in real terms. A bond yielding 3% during 4% inflation loses you money in real terms. Tracking purchasing power forces you to think about money the way it actually behaves over time.
Data sourced from trusted institutions
All formulas verified against official standards.