90 mils is equivilant to what fraction of an inch?

Answer 1

In the United States, One Mil is understood to be one one thousandth of an inch, or 0.001 inches. Mils are frequently used in measuring plastic, film, and sheet materials in applications that do not use the metric system.

90 mils is equal to 0.090 inches, or 90/1000ths of an inch, which reduces to 9/100ths of an inch.

However, fractional parts of inches are normally measured in powers of two (for example, 1/4 inch, 1/8 inch, 1/16 inch, and so on). In this case, we cannot get an exact answer, but we can come acceptably close.

If using thirty-seconds of an inch (1/32), you can get pretty close to 90 mils. 3/32 of an inch is equal to 0.09375 inches, or approximately 94 mils. For most applications, that's probably accurate enough.

For better accuracy than that, you would need to measure in 256ths. 23/256ths of an inch is approximately 0.0898 inches, which is within one mil tolerance of 90 mils.