Methodology

House values

Every trajectory uses the U.S. Federal Housing Finance Agency House Price Index: the quarterly all-transactions series for each metropolitan area. A purchase in year Y is priced at Y’s average index level and scaled to the latest quarter: value = price × idx_latest / mean(idx_Y). The index is built from repeat transactions on the same properties, which controls for the mix of homes that happen to sell.

Median home value

Each metro page opens with the median value of owner-occupied homes in that metro area, from the U.S. Census Bureau’s American Community Survey (ACS), table B25077. The survey asks owners what their home would sell for, and the Census Bureau publishes the median of those answers with a margin of error at 90% confidence. A page uses the 1-year estimate where the metro has one (the Census Bureau publishes those for areas of 65,000 people or more) and the 5-year estimate otherwise, says which, and compares the figure with the US median from the same survey and period. All 410 metros here use the 2024 1-year estimate. Each metro is matched to the Census figures by its metro area code (its division code for a metropolitan division) and its name, and a metro without a match shows no figure. The FHFA index measures how prices changed; the ACS median gives their level.

Mortgage math

The mortgage uses the average 30-year fixed rate for the entry year (Freddie Mac Primary Mortgage Market Survey, via FRED), amortized monthly on a standard 30-year schedule. Equity today = scaled value − remaining balance, and after 30 years the loan is paid off, so the balance is zero. Dividing that equity by the down payment gives the multiple on your cash.

The alternatives

The rent line grows your stated rent with the metro’s HUD 2-bedroom Fair Market Rents (annual, FY1983 onward): every county in the metro's current delineation, the median across those counties, each year's level held for twelve months, summed month by month. Where a metro spans several HUD rent areas, the one named for the principal city is used. Fair Market Rents are HUD's benchmark: roughly the 40th percentile of gross rents for typical units, set per federal fiscal year. HUD's percentile definition has shifted over the decades (45th in the early 1990s, 50th in some areas in the mid-2000s), and the series reflects HUD as published. FY1984 is absent from HUD's consolidated file, so 1983 carries forward one year. A scenario that starts before 1983 falls back to the national CPI rent-of-primary-residence index (BLS via FRED), and the line says so. The market line puts the same down payment in an S&P 500 index fund with dividends reinvested: the TSP C Fund, the Thrift Savings Plan's S&P 500 index fund for federal employees and members of the uniformed services, whose monthly returns the Federal Retirement Thrift Investment Board publishes at tsp.gov. It buys in June of the purchase year and is valued at the latest month the fund has reported. The fund began in January 1988, so a purchase before 1988 has no market line, and a purchase in the current year has none until the fund has reported a month after that June. Both lines are labeled wherever they appear.

Wall Street Regrets answers the stock side of the question (the shares you sold, the coins you didn’t hold) with its own calculator.

Limits

A metro index describes the whole market, and your own house can differ with its block, condition and remodels. Property taxes, insurance, maintenance, transaction costs, PMI, points, refinancing and tax effects are not modeled, and your own rent may have moved differently from HUD’s benchmark. Metro delineations are today’s, applied to the whole history, and the earliest years vary by metro. Nothing here is advice: it is arithmetic about the past.

Sources

FHFA HPI (all-transactions, metro, quarterly; public data; this site is neither endorsed nor certified by FHFA) · U.S. Census Bureau American Community Survey, table B25077, median value of owner-occupied housing units (2024 1-year estimates; US government work) · HUD Fair Market Rents (2-bedroom, FY1983–present; US government work) · Freddie Mac PMMS via FRED · BLS CPI rent via FRED · TSP C Fund monthly returns (Federal Retirement Thrift Investment Board, tsp.gov; this site is not affiliated with or endorsed by the Thrift Savings Plan). The citation data providers request appears here and in every page footer.