Frequently asked questions

Where do the numbers come from?

Official BLS CPI-U data, retrieved via FRED, consumed read-only. Every page states the data date.

How often does the site update?

The site rebuilds when the monthly CPI series updates; the visible date on each page changes when the data changes.

Why does this differ from the BLS calculator?

It shouldn't, materially — we use the same CPI-U ratio method. Differences come from month selection and rounding.

Is this investment advice?

No. We compute what happened to purchasing power. No page tells you what to do.

Does the S&P 500 figure include dividends?

No. We use the price index, without dividends reinvested. The total-return figure would be higher, and we say so on every page where the S&P appears.

Why does bitcoin start in 2011?

Each simulation respects the real start of the data — bitcoin's closing series begins in September 2011, ethereum's in August 2017. We never invent a starting point earlier than the first available data; that is what keeps the comparison honest.

Is a currency a return?

No. A currency is an exchange rate against the dollar, and cash held in it earns no interest — so a rate move is a gain or loss of dollar purchasing power, not a yield. The currency pages say so and compare against U.S. inflation.

How are the home prices measured?

As the typical value per square meter from Redfin sold data — the value of the property itself. It excludes rent collected, leverage, property taxes and maintenance, so it is not an investor's total return.

Descriptive, educational content computed from official public data. Not investment advice. Past performance does not guarantee future results.