What is units from smallest to largest of linear measurement?

The units of linear measurement from smallest to largest are typically millimeters (mm), centimeters (cm), meters (m), and kilometers (km). Millimeters are the smallest commonly used unit, with 10 millimeters in a centimeter, 100 centimeters in a meter, and 1,000 meters in a kilometer. Other units like inches, feet, and miles exist in different measurement systems but follow a similar hierarchical structure.