Inflation Calculator
See what a past amount is worth in another year using approximate U.S. CPI-U annual averages — or project how today’s money erodes (or grows in nominal terms) at a chosen inflation rate.
Calculate
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Result
The formula
Historical mode: Amount_to = Amount_from × (CPI_to ÷ CPI_from) using annual-average CPI-U (1982–84=100). Forward mode: Future = Present × (1 + rate)^years — the same compound-growth math used for inflation projections.
Worked example
- $10,000 in 1990 → CPI≈130.7; in 2024 CPI≈313.7
- Factor ≈ 313.7/130.7 ≈ 2.40
- ≈ $24,000 in 2024 purchasing-power terms
Result: $10k (1990) ≈ $24k (2024) CPI-adjusted
How inflation adjustment works
Price indexes turn “how many dollars” into “how much buying power.”
CPI-U series
We use approximate annual-average Consumer Price Index for All Urban Consumers (CPI-U), indexed to 1982–84=100, in the spirit of BLS publications. Values are rounded teaching approximations — not a substitute for downloading official BLS tables for legal or contractual use.
Forward projection
Compounding at a constant annual rate illustrates purchasing-power loss (or the nominal dollars needed to keep pace). Real returns require subtracting inflation from investment yields separately.
Limits
CPI baskets change; local inflation differs from the U.S. average; housing and healthcare components can diverge. Use country-specific indexes when precision matters outside the U.S.
Interesting facts
Rule of 72
At ~3%/year inflation, prices roughly double in 72÷3 ≈ 24 years — a quick mental check.
Nominal vs real
A 5% raise with 3% inflation is about 2% real. Always compare rates on the same basis.
CPI vs PCE
The Fed often cites PCE; consumers know CPI better. Levels differ slightly; both track inflation.
Deflation years
If the later CPI is lower, adjusted amounts shrink — money gained purchasing power.
Not an investment return
This adjusts for prices — it does not model stock or bond returns.
Frequently asked questions
Choose Historical, enter the amount and both years. We multiply by the ratio of annual CPI-U values.
Set year-from to 1990 and year-to to a recent year (e.g. 2024). The result applies the CPI ratio to $10,000.
Enter today’s amount, an annual inflation rate, and years. FV = amount × (1+rate)^years.
It is an approximate CPI-U teaching series aligned with BLS methodology. Download official series from BLS for contractual or research precision.
Enter $1 with a from-year 30 years back and a to-year of today in historical mode. The calculator multiplies by the ratio of annual-average CPI-U values to show approximate purchasing-power equivalence.
U.S. CPI-U inflation has averaged roughly 2–3% per year over long stretches of modern history, though individual years have ranged from negative (deflation) to double digits. Use the future-value mode with your own assumed rate for projections.
CPI-U tracks a broad national basket of goods and services. Your personal spending mix (housing, healthcare, groceries) can inflate faster or slower than the headline average, so lived experience often diverges from the published rate.
References
- Consumer Price Index (CPI) Official CPI overview and data access.
- CPI inflation calculator BLS’s own dollar-conversion tool.
- Inflation concepts Educational materials on inflation and purchasing power.