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Inflation Calculator
A dollar from one year is not a dollar in another. This US inflation calculator compares any two years with real CPI data to show the change in purchasing power — or switches to a fixed rate to project a future amount.
See how this works on a single $100 bill — 3 real examples
Equivalent value
$0
Cumulative inflation
0%
Average annual rate
0%
Price multiple
1.00×
Value of money over time
CPI data source
Last reviewedYear-by-year breakdownThe equivalent value for each year in the range
| Year | CPI index | Equivalent value |
|---|
How this inflation calculator measures purchasing power
In CPI mode, your amount is scaled by the ratio of the ending year’s Consumer Price Index to the starting year’s:
adjusted = amount × (CPIend ÷ CPIstart)
Cumulative inflation is that ratio minus one, and the average annual rate is the ratio compounded down over the span: (ratio1 / years − 1). For example, the CPI-U rose from about 82.4 in 1980 to roughly 321.9 in 2025, so $100 becomes about $391 — cumulative inflation near 291%, averaging about 3.1% a year.
In fixed-rate mode, there is no CPI lookup — the tool applies one assumed rate i over n years. “Future cost” compounds forward (amount × (1 + i)n) to show the future dollars needed to keep pace; “Today’s value” discounts backward (amount ÷ (1 + i)n) to show today’s purchasing power. Use it to project beyond the historical data or into the future.
The CPI series is the U.S. Bureau of Labor Statistics CPI-U (all urban consumers, U.S. city average, all items, series CUUR0000SA0), annual averages on the 1982–1984 = 100 base, retrieved July 2026. It is stored here as an editable, dated snapshot so the calculator works offline. The 2025 annual average is BLS’s official published figure, but computed from eleven months — October 2025 was never published because of the lapse in appropriations — so it can differ slightly from a naive twelve-month average. BLS explains the gap. These figures track the published data but are not a live or official feed; for authoritative, current numbers, use the Bureau of Labor Statistics.
The same $100, three eras
Two slices of real CPI history and one steady-rate projection, all starting from the same $100 bill.
1995 to 2025: the quiet climb
in 2025 dollars$211.25
- The CPI ratio compounds to 2.11x — $100 of 1995 buying power now takes $211.25.
- Cumulative inflation of 111.2% arrived at an average of only 2.52% a year.
- A bill kept under the mattress since 1995 buys less than half of what it once did.
Decades of unremarkable inflation cut the dollar to less than half its buying power.
Load this example (opens in a new tab)The loud decade
in 1980 dollars$212.37
- Ten years of high inflation carried $100 of 1970 money to $212.37 — prices up 112.4%.
- The pace averaged 7.82% a year, nearly four times the Federal Reserve's modern 2% target.
- Cash held through that stretch surrendered more than half its purchasing power in ten years.
When the annual rate hits high single digits, the doubling clock runs on years, not decades.
Load this example (opens in a new tab)The road ahead at 3%
future cost of $100$242.73
- Matching $100 of today's buying power in thirty years takes $242.73 at a steady 3%.
- Cumulative inflation reaches 142.7% — beyond what the 1970s managed in their decade.
- No CPI lookup here: one assumed rate, compounded, which is the mode built for planning.
Even at 3%, prices multiply 2.43x in a generation — future plans price in future dollars.
Load this example (opens in a new tab)Illustrations only, not financial advice. Your own rate, taxes and insurance will differ — check with a qualified financial advisor before acting on any of this.
What inflation does to a dollar, in plain English
- Inflation is a loss of purchasing power. The same dollar buys less each year. Rising prices and a shrinking dollar are two sides of the same coin — that is why $100 in 1980 needs to be almost $391 today just to break even.
- Small rates compound into big gaps. At the Fed’s 2% target, prices double in about 35 years; at 3%, in about 24; at 7%, in barely 10. The fixed-rate mode makes that doubling visible on the chart.
- “Value of money over time” cuts both ways. Use CPI mode to look back at real history, and fixed-rate mode to look forward — a future salary or price target only holds up if it grows at least as fast as inflation.
- Real return is what counts. A 7% investment return during 4% inflation is only about 3% in real terms. Always judge growth against the rising cost of living, not the headline number.
- The data is dated and honest. The CPI here is a cited BLS snapshot with a “last reviewed” date and a documented caveat on the latest year — check the BLS for the authoritative figure before quoting it.
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Frequently asked questions
What is $100 from 1980 worth today?
About $391. The CPI-U rose from roughly 82.4 in 1980 to about 321.9 in 2025 — a factor of 3.91 — so $100 in 1980 has the same purchasing power as roughly $391 today. That is cumulative inflation of about 291%, or an average of ~3.1% a year. Change the amount and years above to run any "[year] to today" comparison; the scenario is saved in the URL so you can share it.
How is inflation calculated in this CPI inflation calculator?
In CPI mode it scales your amount by the ratio of the ending year’s Consumer Price Index to the starting year’s: adjusted = amount × (CPI_end ÷ CPI_start). The cumulative inflation is that ratio minus one, and the average annual rate is the ratio compounded down over the number of years. In fixed-rate mode it instead applies your assumed rate as amount × (1 + rate)^years.
What is the CPI (Consumer Price Index)?
The CPI measures the average change over time in the prices urban consumers pay for a fixed basket of goods and services — housing, food, transportation, medical care and more. This tool uses the BLS CPI-U (all urban consumers, U.S. city average, all items), the most common headline series, indexed so the 1982–1984 average equals 100.
What is a normal inflation rate?
The Federal Reserve targets about 2% a year over the long run. Actual US inflation has swung far wider: near zero (or briefly negative) during recessions, but double digits in the late 1970s and early 1980s, peaking around 13.5% in 1980. Over the last century it has averaged roughly 3% annually.
What is the difference between CPI mode and fixed-rate mode?
CPI mode uses real historical BLS data to compare two actual calendar years (1913–2025) — best for "what was money worth then" questions. Fixed-rate mode applies one assumed inflation rate over a number of years, in either direction: project what an amount will need to be in the future, or discount a future amount back to today’s purchasing power. Use fixed-rate for planning past the data range.
Can I calculate inflation up to 2026?
The latest full-year figure in this dataset is the 2025 annual average — the Bureau of Labor Statistics has not yet published a 2026 annual average, so "today" here means the most recent complete year. For a mid-2026 estimate, use fixed-rate mode with a rate near 3% and one extra year, or check the BLS site for the current month’s index.
How does inflation affect my investment returns?
Inflation erodes the real value of money over time, so what matters is your return after inflation. Real return ≈ nominal return − inflation: a 7% nominal return during 4% inflation is only about 3% in purchasing power. That is why long-term plans should compare growth against the rising cost of living, not just the headline rate.
Are these the official BLS inflation numbers?
The CPI values here are the well-known BLS CPI-U annual averages, transcribed as an editable, dated snapshot (last reviewed July 2026) so the calculator runs offline. They are accurate to the published figures, but this is a transcription, not a live feed. The 2025 annual average is BLS’s official published figure, but computed from eleven months — October 2025 was never published because of the lapse in appropriations — so it can differ slightly from a naive twelve-month average. For authoritative, current data, go to the Bureau of Labor Statistics.
Disclaimer: these calculators are educational tools, not financial advice. They model your inputs with published formulas, but they cannot know your full situation — for decisions with real stakes, talk to a qualified professional. Formulas and defaults last reviewed .