How long does the money in your pocket last before it is replaced?

That depends on the denomination of the note. A $1 bill lasts 18 months; $5 bill, two years; $10 bill, three years; $20 bill, four years; and $50 and $100 bills, nine years. Bills that get worn out from everyday use are taken out of circulation and replaced.

The Bureau of Engraving and Printing produces 38 million notes a day with a face value of approximately $541 million. That doesn't mean there is $541 million more money circulating today than there was yesterday, though, because 95% of the notes printed each year are used to replace notes already in circulation. In other words, longevity of any piece of currency is a function of it denomination. No wonder those hard-earned, rarely seen 100 dollar Franklins always look so crisp. At least until Inflation catches up.  ¶ 3:23 AM