---
title: "About"
description: "Who builds ValueThen, where the data comes from, and how the calculator is funded."
url: "https://valuethen.com/about/"
language: "en"
site: "ValueThen"
publisher: "Rising Throne"
updated: "2026-09-02"
license: "Data: World Bank CC BY 4.0, ECB, FRED"
---

# About

Who builds ValueThen, where the data comes from, and how the calculator is funded.
# About ValueThen

ValueThen answers one question as directly as possible: what an amount of money from an earlier year is worth today, in the same currency or in another one. It covers 39 currencies, most of them back to 1960, and it is free to use with no account and no advertising.

## Who builds it

The site is built and operated by Rising Throne, a small software company that also publishes Money Visualiser, a tool for seeing the physical size of cash amounts, and PaperXtrade, a paper-trading environment. We build focused financial tools that do one thing precisely rather than broad dashboards. You can reach a person at [contact@therisingthrone.com](mailto:contact@therisingthrone.com?subject=valuethen.com).

## Where the numbers come from

Consumer price indices come from the World Bank, the European Central Bank for the euro area, and the Federal Reserve Bank of St. Louis for recent United States data. Exchange rates are European Central Bank reference rates, extended before 1999 by a commercial historical rates provider. We publish no estimates of our own: every figure is a direct arithmetic result from a named official series, and the series behind any result is printed underneath it.

## How it is funded

There are no ads, no trackers and no paid tiers on this site. It is funded by our other products, which is why you will find one link to Money Visualiser on the home page. The public API is free and needs no key. If usage ever outgrows that model we will say so on this page before changing anything.

## Corrections

If a number looks wrong, tell us which currency, which years and what you expected, and we will check the underlying series and reply. Data corrections take priority over everything else we are working on.

## Use this page programmatically

The same figure from the free API, no key required:

```bash
curl "https://api.valuethen.com/v1/convert?amount=100&from=USD&to=EUR&fromYear=1970&toYear=2026"
```

```json
{ "result": 777.71, "method": "cpi-then-fx", "sources": ["World Bank FP.CPI.TOTL, 2010=100"] }
```

---

Data sources: World Bank FP.CPI.TOTL, ECB HICP and reference rates, FRED CPI-U.
Free JSON API: https://api.valuethen.com/openapi.json · Agent guide: https://valuethen.com/llms.txt · MCP: https://api.valuethen.com/mcp