# What is a dollar worth after inflation?

Converts dollars from one month to another since 1913 with the US CPI-U (BLS), with the total and yearly inflation.

- Page: https://www.acalculator.org/finance/inflation-calculator
- JSON spec: https://www.acalculator.org/finance/inflation-calculator.json
- Version: deab82c119b1

## Default answer

Example with the default inputs (Amount $100.00, In (start month) January 1, 2000, Is worth in (end month) August 1, 2026): $100.00 in January 2000 has the same buying power as $198.45 in August 2026.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| amount | Amount | The dollar amount in the start month. |
| from | In (start month) | Any day of the month, from January 1913. |
| to | Is worth in (end month) | Any day of the month, up to August 2026. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Worth in the end month | Amount × end CPI ÷ start CPI. |
| inflation | Total inflation | The price change between the months. |
| yearlyRate | Average inflation a year | The yearly rate that compounds to the total. |
| startCpi | CPI in the start month | CPI-U, 1982-84 = 100. |
| endCpi | CPI in the end month | CPI-U, 1982-84 = 100. |
| startMonth | Start month | The month of the start CPI. |
| endMonth | End month | The month of the end CPI. |

## Method

Value = amount × end CPI ÷ start CPI; yearly rate = (CPI ratio)^(12 ÷ months) − 1.

## Assumptions

- CPI-U, all items, US city average, not seasonally adjusted (BLS series CUUR0000SA0).
- Each date stands for its month; the day is ignored.
- October 2025 has no CPI (BLS did not collect it).

## Worked examples

1. amount = $100.00, from = 2000-01-01, to = 2026-01-01 gives value = $192.68, inflation = 92.684834%, yearlyRate = 2.554725%, startCpi = 168.8, endCpi = 325.252. Source: BLS CPI-U (Jan 2000 168.8, Jan 2026 325.252).
2. amount = $1,000.00, from = 2026-01-15, to = 2000-01-31 gives value = $518.98. Source: BLS CPI-U.
3. amount = $1.00, from = 1913-01-01, to = 2026-01-01 gives value = $33.19, startCpi = 9.8. Source: BLS CPI-U (Jan 1913 9.8).

## FAQ

### How does an inflation calculator work?

It scales the amount by the ratio of two Consumer Price Index values. The CPI-U was 168.8 in January 2000 and 325.252 in January 2026, so $100 in January 2000 buys what $192.68 bought in January 2026: prices rose 92.68%, about 2.55% a year.

### Which CPI does this use?

The Consumer Price Index for All Urban Consumers (CPI-U), all items, US city average, not seasonally adjusted, from the Bureau of Labor Statistics (series CUUR0000SA0). It is the index behind the BLS CPI inflation calculator and most published inflation rates.

### Why is there no October 2025?

BLS did not collect October 2025 prices during the 2025 lapse in federal appropriations, and it did not publish a CPI for that month. Pick September or November 2025 instead.

### How current is the data?

The page is built with the latest CPI month BLS had published; the result shows that month. BLS publishes each month’s CPI in the middle of the next month.

### Is this the same as the Social Security COLA?

No. Social Security cost-of-living adjustments use the CPI-W (urban wage earners) and compare July to September averages. Use the COLA calculator for benefits.

## Sources

- U.S. Bureau of Labor Statistics, Consumer Price Index for All Urban Consumers (CPI-U), series CUUR0000SA0: https://data.bls.gov/timeseries/CUUR0000SA0
- U.S. Bureau of Labor Statistics, CPI Inflation Calculator (method): https://www.bls.gov/data/inflation_calculator.htm
- U.S. Bureau of Labor Statistics, CPI data during the 2025 lapse in appropriations (October 2025 not collected): https://www.bls.gov/cpi/