The smallest measure of length among millimeters, centimeters, inches, and miles is the millimeter.
To compare:
- 1 millimeter (mm) = 0.1 centimeters (cm)
- 1 centimeter (cm) = 10 millimeters (mm)
- 1 inch = 25.4 millimeters (approximately)
- 1 mile = 1,609,344 millimeters (approximately)
So, the order from smallest to largest is: millimeter < centimeter < inch < mile.