Money Supply Calculator
CPI tracks prices. This tracks the other side of the ledger: how much the supply of dollars itself has grown, and what your share of it has become. Based on M2 back to 1959.
M2 vs CPI: two measures of the same erosion
Since your chosen year, the two numbers usually disagree — and the gap is the story. CPI measures what consumers pay for a basket of goods; M2 measures how many dollars exist. When M2 grows faster than CPI, the difference has historically shown up in asset prices (housing, equities) rather than groceries, which is why savers can feel poorer even when official inflation looks tame.
Keeping your share means this: if you held X dollars when total M2 was Y, you owned X÷Y of all U.S. money. The figure above is what you would need today to own that same fraction. It is a dilution measure, not a price measure — no basket, no substitutions, no hedonic adjustments. Just your slice of the pie as the pie grew.
Methodology
M2 figures are annual averages of the monthly, seasonally adjusted series (M2SL) from the Federal Reserve's H.6 release; CPI comparison uses annual average CPI-U from the Bureau of Labor Statistics. Both retrieved via FRED. Formula: equivalent = amount × (M2now ÷ M2then). For the price-basket view of the same question, use the inflation calculator.