1/16 = 0.0625. Get a calculator and divide your decimal measurement by 0.0625, then that is the number of 1/6ths. From there reduce the fraction to what you want.
For example 0.4375 / 0.0625 = 7. So it is 7/16
0.75 / 0.0625 = 12. So it is 12/16 or 3/4