Convert from digit to tu

Unit Definition (digit)
The digit is a historic unit of distance equal to the width of a person's finger. Used in all the ancient civilizations of the Middle East and Mediterranean, the digit was equal to 0.75 inch or 19 millimeters with only the smallest variations. Typically, there were 4 digits in a palm, 16 in a foot, and 24 (sometimes 28) in a cubit. The word digit is from the Latin word for a finger or toe, digitus.

Unit Definition (tu)
The tu is a traditional Chinese unit of distance equal to 250 li. Using the late nineteenth century definition of the li as 2115 feet, the tu was equal to 100.14 miles or 161.13 kilometers.