How many mils are in 0.001 inches?

One mil is defined as one-thousandth of an inch, which is equivalent to 0.001 inches. Therefore, when you are asked how many mils are in 0.001 inches, you can directly see that 0.001 inches is equal to 1 mil. This is a straightforward conversion based on the definition of a mil.

The other options represent values that do not align with this definition; for instance, 10 mils would correspond to 0.01 inches, and 100 mils would equal 0.1 inches, both of which exceed the given measurement of 0.001 inches. Consequently, the correct understanding of the conversion leads to recognizing that 0.001 inches precisely equals 1 mil.