See how inflation erodes purchasing power over time. Adjust any dollar amount to today's value or any past or future year.
Results update live as you type.
Adjusted Value
Adjusted Value
$2,094
in target year
Cumulative Inflation
109.38%
over 25 years
Value Change
+$1,094
inflation gain
Buying Power Today
47.76%
of original
| Year | Value | Cumulative Inflation |
|---|
The Formula
Inflation is modelled using the compound interest formula. Each year's inflation is applied to the previous year's value — so a 3% rate doesn't simply add 3% × years; it compounds, meaning the total impact grows faster than a linear calculation. This is the same formula used in CPI-based purchasing power adjustments.
Formula
About This Tool
An inflation calculator — also called a purchasing power calculator or CPI calculator — is a free tool that shows you how the real value of money changes over time due to inflation. Enter an original dollar amount, a starting year, an ending year, and an average annual inflation rate, and the calculator instantly shows you the equivalent value adjusted for inflation.
Our CPI inflation calculator uses the compound interest formula to model inflation precisely. It doesn't just multiply years by the rate — it compounds each year's inflation on top of the previous year, exactly as the Consumer Price Index (CPI) tracks prices in practice. The result is a highly accurate estimate of how much goods and services that cost a certain amount in a past year would cost today — or will cost in the future.
Use this tool to understand the real return on savings and investments, compare historical prices to today's equivalent, model how future inflation will erode purchasing power, or explain to clients why a fixed benefit loses real value over time.
The year-by-year table and chart give you a complete picture of the inflation path, while the breakdown donut chart shows exactly how much of the adjusted total represents genuine inflation versus the original principal.
Compound Inflation
Uses the accurate compound formula, not a simple linear estimate.
Year-by-Year Chart
Visualise how the value grows or erodes across every year in the range.
Custom Rate
Enter any inflation rate — the Fed 2% target, historical avg 3.1%, or custom.
Forward & Backward
Calculate from past to present or future to see both directions of adjustment.
100% Private
No data stored. All calculations run locally in your browser.
Year-by-Year Table
Full table of equivalent values and cumulative inflation for every year.
Four inputs give you a complete inflation-adjusted value in seconds.
Type or slide the dollar amount you want to adjust — this is the starting value before inflation is applied.
Enter the starting year (when the original amount is measured) and the ending year (the target year you want to convert to).
Use 3% for the US historical average, 2% for the Fed target, or enter a custom rate to model different scenarios.
The Over Time chart shows the complete growth path, the Breakdown tab shows the split between original and inflation gain, and the Table tab gives year-by-year detail.
The "Buying Power Today" stat shows what percentage of the original purchasing power remains — telling you how much value has been eroded.
Adjust the rate to compare high-inflation (8%) vs. low-inflation (2%) futures. Use it to stress-test retirement savings against different CPI scenarios.
Everything you need to know about inflation, CPI, and purchasing power.
Inflation is the rate at which the general price level of goods and services rises over time, eroding the purchasing power of money. For consumers, it means the same amount of money buys less each year. For investors, it means returns must exceed the inflation rate to generate real wealth growth. For retirees, it means fixed incomes become less valuable over time — making inflation one of the biggest risks in long-term financial planning.
US CPI inflation has averaged approximately 3.1% per year since 1913. The Federal Reserve targets 2% as a healthy long-run average. Notable periods include the 1970s oil crisis (~8–10%), post-2008 era (~1–2%), and the 2021–2022 spike to over 8% driven by supply-chain disruptions and fiscal stimulus. For general planning purposes, using 2.5–3.5% is a reasonable assumption.
The Consumer Price Index (CPI), published by the Bureau of Labor Statistics, measures the change in price of a fixed basket of goods and services. The Personal Consumption Expenditures (PCE) index, published by the Bureau of Economic Analysis, is the Federal Reserve's preferred measure — it adjusts for changes in consumer behaviour and tends to run ~0.3–0.5% lower than CPI. This calculator uses a simple compounding model compatible with either measure depending on the rate you enter.
Inflation erodes the real return on any asset. A savings account earning 2% while inflation runs at 3% is actually losing 1% in real purchasing power per year. The "real return" is the nominal return minus the inflation rate. To preserve and grow wealth, investments must consistently outpace inflation — historically, a diversified equity portfolio has returned 7–10% nominally, or 4–7% in real terms after inflation.
This calculator is mathematically exact for the constant rate you enter. Real-world inflation varies year to year — it is not constant. For historical calculations between specific years, you would need actual CPI data from the Bureau of Labor Statistics rather than a constant rate assumption. Use the calculator for planning, scenario modelling, and educational purposes rather than auditing historical purchasing power precisely.
The Rule of 70 is a quick mental estimate: divide 70 by the annual inflation rate to find approximately how many years it takes for the purchasing power of money to be cut in half. At 2% inflation, purchasing power halves in ~35 years. At 3.5%, it halves in ~20 years. At 7%, it halves in just 10 years. This rule shows how dramatically higher inflation rates accelerate the erosion of value.