How much U.S. paper currency is in circulation?

How to get close to this number

Take the per-person figure and multiply. The explanation gives roughly seven thousand dollars for every resident, across a population of some three hundred and forty million. Per-person times population gives a figure in the low trillions.

Seven thousand dollars each is obviously not what anyone carries — this site's European cash question puts a wallet at around sixty euros. The gap is the clue: most physical currency is not circulating in wallets but sitting in vaults, mattresses and safes, held as a store of value rather than used as a medium of exchange.

The offshore estimate is the resolution: the central bank believes well over half of all its paper money is held outside the country. A national currency functioning as a global store of value means most of its physical notes never enter the domestic economy at all — which is why cash in circulation keeps rising in a country where domestic cash use keeps falling.