The SI system of units is used universally among the micromanufacturing community. The base unit is the meter and smaller units are based on standard prefixes of milli (10E-03 "one-thousandth"), micro (10E-06 "one-millionth"), and nano (10E-09 "one-billionth"). One Angstrom unit is one-tenth of a nanometer (10E-10). The magnitude of such small quantities are not in the realm of normal, everyday experience. A few equivalents, expressed in multiple units, may help with the realization of these quantities.

• 1 million seconds is more than 11.5 days.
  
• 1 billion sheets of writing paper would make a stack approximately 100 km (63 miles) high.
  
• 10 billion US dimes, placed edge-to-edge, would stretch nearly half the distance to the Moon.

Click this graphic to see additional size comparisons at the microscale.

While there are significant variations in fabrication processes and the capabilities of instrumentation, some approximate ranges and values are:

!! It is important to note that the resolution of metrology tools is given, and not the accuracy or repeatability. The resolution is a function of the instrument's design and rarely defines an instrument's performance. These differences are presented in Precision Engineering and Practices.