* Dimensions of a Dollar Bill: A standard US dollar bill is about 6.14 inches long.

* Stacking: Let's assume the bills are stacked perfectly on top of each other, with no extra space.

* Calculation:

* 1,000,000 (dollars) x 6.14 inches/dollar = 6,140,000 inches

* Convert to feet: 6,140,000 inches / 12 inches/foot = 511,666.67 feet

* Convert to miles: 511,666.67 feet / 5280 feet/mile = 96.8 miles

Therefore, a stack of one million US dollar bills would be about 96.8 miles tall!