Coverage and unavailable data
The snapshot covers January 1913 through 2026-08. 2025-10: Data unavailable due to the 2025 lapse in appropriations. Unavailable months are excluded; they are not filled with estimates.
Planning
US Inflation Calculator — Historical Dollar Value
Compare dollar purchasing power between published months since 1913 using official BLS CPI-U data. Calculate cumulative inflation and equivalent U.S. dollar value.
Equivalent U.S. dollars in 2026-08
$198.45
Cumulative inflation in selected direction
98.45%
Annualized CPI change in selected direction
2.61%
Change in equivalent dollar amount
$98.45
Starting CPI
168.8
Comparison CPI
334.98
Historical CPI and equivalent dollars
Detailed values use the same assumptions as the summary above.
| Month | CPI-U index | Equivalent U.S. dollars |
|---|---|---|
| 2000-01 | 168.8 | 100 |
| 2000-02 | 169.8 | 100.592 |
| 2000-03 | 171.2 | 101.422 |
| 2000-04 | 171.3 | 101.481 |
| 2000-05 | 171.5 | 101.6 |
| 2000-06 | 172.4 | 102.133 |
| 2000-07 | 172.8 | 102.37 |
| 2000-08 | 172.8 | 102.37 |
| 2000-09 | 173.7 | 102.903 |
| 2000-10 | 174 | 103.081 |
| 2000-11 | 174.1 | 103.14 |
| 2000-12 | 174 | 103.081 |
Historical consumer-price changes describe an average basket, not your individual expenses or an investment return. Only published monthly observations are selectable; no missing values are interpolated.
Calculation method
Formula and method
Cumulative inflation is the CPI ratio minus one, multiplied by 100%. For example, January 2000 CPI was 168.8 and January 2020 CPI was 257.971: 100 dollars in the first month corresponds to about 152.83 dollars in the second.
Detailed guide
Compare the purchasing power of a dollar over time
Enter a dollar amount and two published months. The calculator applies the ratio of the Consumer Price Index to estimate how much money in the comparison month buys the same average basket as the original amount.
This historical calculation uses the BLS CPI-U all-items U.S. city average without seasonal adjustment. Choose months in either direction to compare older prices with newer prices or express a later amount in earlier dollars.
Formula and method
Equivalent dollars = original dollars × CPI(comparison month) / CPI(starting month)
Cumulative inflation is the CPI ratio minus one, multiplied by 100%. For example, January 2000 CPI was 168.8 and January 2020 CPI was 257.971: 100 dollars in the first month corresponds to about 152.83 dollars in the second.
The annualized change converts the selected ratio over the number of months into a compound yearly rate. It is zero for the same month and negative when the selected comparison direction reduces the index.
Using the results
Monthly versus annual comparisons
This calculator compares specific months. A calculator based on annual-average CPI can give a different result because it averages prices across the year.
Dollar value and exchange rates
The result measures U.S. consumer purchasing power. It does not convert currencies or model exchange-rate changes.
Frequently asked questions
Where does the historical inflation data come from?
The source is BLS series CUUR0000SA0, CPI-U all items for the U.S. city average, not seasonally adjusted. The snapshot date and latest available month are displayed above the form.
Can I calculate from a newer month to an older one?
Yes. Select the later starting month and an earlier comparison month. The ratio expresses the later amount in earlier purchasing-power terms.
Does this forecast future inflation?
No. It uses published historical CPI. For a future scenario, use the separate inflation calculator and enter your own assumed rate.
Data sources
These sources explain the concepts used in the calculation. Check the applicable contract or issuer documents for your actual parameters.
Updated: October 1, 2026
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