How big is $100 dollar in usa?

Excuse me, could you please clarify what you mean by "How big is $100 dollar in usa?" Are you referring to the physical size of a $100 bill in the United States, or are you asking about the value or purchasing power of $100 in the American economy? If you're inquiring about the size of the bill, it's a standard size that's roughly 6.14 inches by 2.61 inches, similar to other denominations in the U.S. currency system. However, if you're wondering about the value or what you can buy with $100, that can vary greatly depending on the goods and services being purchased, as well as factors like inflation and economic conditions.