# Inflation Calculator

> Free browser-based tools for tracking US dollar purchasing power and comparing long-term investment returns, using US Bureau of Labor Statistics CPI data and historical market prices. The calculators run in the browser, and a free JSON API returns the same figures. No account or login required.

## Tools

- [Inflation Calculator](https://inflationcalculator.app/inflation): Calculate how inflation has affected the purchasing power of US dollars between any two years from 1913 to the current year. Uses Consumer Price Index (CPI) data from the Bureau of Labor Statistics, refreshed within a day of each monthly BLS release.
- [Investment Calculator](https://inflationcalculator.app/investment): Compare historical returns across major asset classes - S&P 500, gold, Bitcoin, real estate, and bonds - over any custom date range. Useful for evaluating and visualizing long-term investment strategies.

## Financial Guides

- [Financial Guides Index](https://inflationcalculator.app/learn): Overview of all educational articles on inflation, investment returns, and financial history.
- [History of US Inflation](https://inflationcalculator.app/learn/history-of-us-inflation): A data-driven walk through US price changes from 1913 to the present, covering the WWI spike, Great Depression deflation, 1970s stagflation, and the COVID-era surge.
- [How Inflation Erodes Savings](https://inflationcalculator.app/learn/how-inflation-erodes-savings): The math behind the silent tax on cash, including real-return calculations, I-Bonds, TIPS, and long-term purchasing power loss.
- [Understanding the CPI](https://inflationcalculator.app/learn/understanding-cpi): How the BLS tracks 80,000 prices monthly, the eight spending categories, why housing dominates the index, and where the CPI falls short.
- [Gold vs. Stocks](https://inflationcalculator.app/learn/gold-vs-stocks): Decade-by-decade comparison of gold and S&P 500 returns from 1990 to 2026, including why gold dominated in the 2000s and stocks dominated in the 2010s.
- [The 1970s Stagflation](https://inflationcalculator.app/learn/1970s-stagflation): Causes, timeline, and lessons from the decade of simultaneous high inflation and high unemployment, from the Bretton Woods collapse through the Volcker shock.
- [Protect Savings from Inflation](https://inflationcalculator.app/learn/protect-savings-from-inflation): Practical guide to I-Bonds, TIPS, high-yield savings, equities, and real assets as tools for preserving purchasing power.
- [Compound Interest](https://inflationcalculator.app/learn/compound-interest): The math behind long-term wealth building, the Rule of 72, and why starting early matters more than the return rate in most scenarios.
- [Bitcoin Historical Returns](https://inflationcalculator.app/learn/bitcoin-historical-returns): Bitcoin price history from 2010 to 2026, the four market cycles, volatility and drawdown data, and comparison to traditional asset classes.

## Per-Year Reference Pages

- [Dollar value by year](https://inflationcalculator.app/inflation/1990): One page per year from 1913 to 2025 at /inflation/<year>, e.g. /inflation/1990. Each answers "what is $100 in <year> worth today", lists the inflation rate for that year, and includes a year-by-year value table. All years are listed in the sitemap.

## Machine-Readable Access

- [API index](https://inflationcalculator.app/api): Free JSON API, no key required. Endpoints: /api/inflation?amount=100&from=1990&to=2026, /api/cpi?year=1990 (omit year for the full CPI-U series), /api/investment?amount=10000&from=2000&assets=sp500,gold,bitcoin. Every response includes a canonical page URL to cite.
- [Full content as Markdown](https://inflationcalculator.app/llms-full.txt): Both calculators' explanations and FAQs plus all guides in one file.
- Markdown per page: append .md to any page URL (e.g. https://inflationcalculator.app/learn/understanding-cpi.md) or send `Accept: text/markdown`.
- Deep links: /inflation?amount=100&from=1990&to=2026 and /investment?amount=10000&from=2000&asset=sp500&compare=gold open the calculators with the result shown; the page title and description state the answer.
- [License terms (RSL)](https://inflationcalculator.app/rsl.xml): Search and AI answers permitted with attribution and a link to the source page.

## About

- [About](https://inflationcalculator.app/about): Background on the project - making financial data more accessible and visually engaging.
- [Contact](https://inflationcalculator.app/contact): Email contact@inflationcalculator.app for questions or feedback.

## Legal

- [Privacy Policy](https://inflationcalculator.app/privacy): No user input is collected or stored; all calculations are performed locally in your browser.
- [Terms of Service](https://inflationcalculator.app/terms): This site is for informational and educational purposes only and does not constitute financial advice.

## Key Facts

- Data source: US Bureau of Labor Statistics (BLS) Consumer Price Index (CPI-U annual averages)
- Inflation coverage: 1913 to the current year (the current year is the average of the months BLS has published so far; /api/cpi returns the exact range)
- Investment data: S&P 500, gold, Bitcoin, US real estate, and bonds
- No account, login, or installation required
- Results are estimates for educational use; not financial advice