Inflation Calculator
Gauge the real purchasing power of currency across historical inflation rates and future forecasts.
Parameters & Inputs
Summary & Breakdown
Purchasing Power Degradation Over Time
About the Inflation Calculator
Inflation represents the steady erosion of currency purchasing power over time. As prices for consumer goods, healthcare, housing, and energy rise, each dollar buys fewer products and services.
Over long horizons like retirement planning, failing to account for inflation can be devastating. A nest egg that appears substantial today may have half its purchasing power 20 years later.
This calculator computes both forward future costs and backward real purchasing power based on chosen annual inflation benchmarks.
How the Calculations Work
Calculations use the compound inflation formula to project future nominal costs and discounted real purchasing power.
Future Cost = Amount * (1 + i)^t, Real Power = Amount / (1 + i)^t
Variables & Definitions
- Amount: Present or future currency denomination
- i: Average annual inflation rate (decimal)
- t: Elapsed duration in years
Assuming $100,000 today and constant 3.5% inflation over 20 years: Future equivalent cost is $100,000 * (1.035)^20 = $198,979. Conversely, receiving $100,000 in 20 years will purchase what $50,257 buys today.
Key Terms Explained
Consumer Price Index (CPI)
A monthly measure examining the weighted average of prices of a basket of consumer goods and services.
Purchasing Power
The quantity of goods and services that can be bought with one unit of currency.
Real Return
The actual rate of return on an investment adjusted for inflation (Nominal Rate - Inflation Rate).
Hyperinflation
Rapid, out-of-control price increases typically exceeding 50% per month.
Practical Tips & Pitfalls to Avoid
Invest to beat inflation
Holding excessive cash in low-yield checking accounts guarantees a steady loss of purchasing power.
Own real assets
Equities, real estate, and inflation-protected bonds (TIPS) historically outpace inflation over multi-decade periods.
Review fixed pension terms
Pensions without Cost-of-Living Adjustments (COLA) lose substantial value over a 30-year retirement.
Model conservative inflation
When building retirement models, using 3% to 3.5% inflation provides a safer margin of error.
Frequently Asked Questions
US headline inflation has averaged approximately 3.2% annually over the last century.
A $100,000 sum will have the purchasing power equivalent to approximately $50,257 in today's money.
Demand-pull inflation (demand exceeding supply), cost-push inflation (rising production costs), and monetary expansion.
Treasury Inflation-Protected Securities€”government bonds whose principal adjusts upward with the Consumer Price Index.
Yes. Sustained negative inflation is called deflation, which can discourage consumer spending and create economic recessions.