# BLS API: Convert US dollars between months with CPI

> Converts a US dollar amount from one month or annual average to another using the US city average CPI-U for all items, not seasonally adjusted. Defaults to the latest published month.

Unofficial. Not affiliated with or endorsed by BLS.

- Page: https://fous.com/methods/bls.gov/calculate-inflation
- Method: `bls.gov/calculate_inflation`, version 1
- Website: bls.gov
- Returns: adjusted amount, cumulative inflation percent, CPI values, plain-English sentence
- Effect: read (it gets data and changes nothing)
- Sign-in: none needed
- Cost: 1 credit per completed run (1¢ with pay as you go); failed runs are free

## Inputs

| Field | Type | Required | In the run below | Description |
|---|---|---|---|---|
| `amount` | number | yes | `100` | Original US dollar amount, for example 100. |
| `end_month` | string | no |  | Destination month, such as 2024-08, or 2024 for its annual average. Defaults to the latest published month. |
| `start_month` | string | yes | `"1995-06"` | Month the money is from, such as 1995-06; use 1995 for its annual average. |

## Output

From a run on Oct 23, 2026. Its input:

```json
{
  "amount": 100,
  "start_month": "1995-06"
}
```

Its output:

```json
{
  "end_cpi": 336.94,
  "currency": "USD",
  "sentence": "$100 in June 1995 has the same buying power as $220.94 in September 2026.",
  "end_month": "2026-09",
  "start_cpi": 152.5,
  "source_url": "https://www.bls.gov/data/inflation_calculator.htm",
  "start_month": "1995-06",
  "adjusted_amount": 220.94,
  "original_amount": 100,
  "cumulative_inflation_percent": 120.94
}
```

## Run it

From code, with a Fous API key in `FOUS_API_KEY`; the answer's `data` holds the output:

```bash
curl https://api.fous.com/v1/runs \
  -H "Authorization: Bearer $FOUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"method":"bls.gov/calculate_inflation","input":{"amount":100,"start_month":"1995-06"}}'
```

From an AI agent connected to the Fous MCP server: its `run` with the same method and input. To connect one, give it `set up https://fous.com/SKILL.md`.

## Ask your agent

- How much is 250 dollars in 1985 worth in today's money using CPI?
- What would 75,000 dollars from March 2001 be worth in August 2024?
- Adjust 1200 dollars from the 1990 annual average to the 2023 annual average for inflation
- On bls.gov, convert 500 dollars from June 1978 to the latest month's purchasing power
- How much did prices rise between 2010 and 2022 if I had 40 dollars in 2010 and want the equivalent in 2022?

## Input schema

```json
{
  "type": "object",
  "required": [
    "amount",
    "start_month"
  ],
  "properties": {
    "amount": {
      "type": "number",
      "minimum": 0,
      "description": "Original US dollar amount, for example 100."
    },
    "end_month": {
      "type": "string",
      "pattern": "^[0-9]{4}(-[0-9]{2})?$",
      "description": "Destination month, such as 2024-08, or 2024 for its annual average. Defaults to the latest published month."
    },
    "start_month": {
      "type": "string",
      "pattern": "^[0-9]{4}(-[0-9]{2})?$",
      "description": "Month the money is from, such as 1995-06; use 1995 for its annual average."
    }
  }
}
```

## Output schema

```json
{
  "type": "object",
  "required": [
    "original_amount",
    "adjusted_amount",
    "currency",
    "cumulative_inflation_percent",
    "start_cpi",
    "end_cpi",
    "start_month",
    "end_month",
    "sentence",
    "source_url"
  ],
  "properties": {
    "end_cpi": {
      "type": "number",
      "description": "CPI-U used for the destination month or year."
    },
    "currency": {
      "type": "string",
      "description": "Currency code for both amounts."
    },
    "sentence": {
      "type": "string",
      "description": "Plain-English comparison of purchasing power."
    },
    "end_month": {
      "type": "string",
      "description": "Destination month (YYYY-MM) or annual average year (YYYY)."
    },
    "start_cpi": {
      "type": "number",
      "description": "CPI-U used for the original month or year."
    },
    "source_url": {
      "type": "string",
      "description": "BLS inflation calculator page."
    },
    "start_month": {
      "type": "string",
      "description": "Original month (YYYY-MM) or annual average year (YYYY)."
    },
    "adjusted_amount": {
      "type": "number",
      "description": "Equivalent amount in US dollars, rounded to cents."
    },
    "original_amount": {
      "type": "number",
      "description": "Original amount in US dollars."
    },
    "cumulative_inflation_percent": {
      "type": "number",
      "description": "Change in purchasing-power-equivalent dollar amount, in percent."
    }
  }
}
```

## See more

- [BLS API: Get inflation rate](https://fous.com/methods/bls.gov/get-inflation-rate.md): Gets the latest U.S. Consumer Price Index inflation for a spending category, with up to 24 recent months of history. Monthly changes are seasonally adjusted; 12-month changes are not.
- [BLS API: Get occupation wages](https://fous.com/methods/bls.gov/get-occupation-wages.md): Finds the latest published BLS pay and employment for an occupation in the US, a state, or a metro area, and compares it with the national median.
- [BLS API: Get unemployment rate](https://fous.com/methods/bls.gov/get-unemployment-rate.md): Gets the latest seasonally adjusted unemployment rate and labor-force counts for the United States or a state, with up to 24 months of history.
- [BLS API: Get occupation outlook](https://fous.com/methods/bls.gov/get-occupation-outlook.md): Finds the best-matching Occupational Outlook Handbook profile for a job title and returns its pay, entry requirements, jobs and 10-year outlook.
- [European Union API: Convert currency](https://fous.com/methods/ecb.europa.eu/convert-currency.md): Converts an amount between currencies using ECB euro reference rates, including euro and cross-currency conversions. Uses the latest preceding published rate when the date has none.
- [Google API: Convert currency amount](https://fous.com/methods/google.com/convert-currency.md): Converts an amount between two currencies using the current Google Finance quote. Rates may be delayed.
- [XE API: Convert currency](https://fous.com/methods/xe.com/convert-currency.md): Converts an amount between two currencies using XE's displayed mid-market rate. It also returns the rate time and an XE converter link. Rates are informational, not transfer quotes.
- [Macrotrends API: Get long-term price history](https://fous.com/methods/macrotrends.net/get-long-term-price-history.md): Gets decades of yearly commodity or stock-index price history from Macrotrends: yearly average, open, high, low, close, annual change and inflation-adjusted value for gold, silver, crude oil, natural gas, copper, Dow Jones, S&P 500 and Nasdaq. The current year may be incomplete.
- [All BLS methods](https://fous.com/methods/bls.gov.md)