These are US and Metric Units.

US Units

Name Symbol Example
inches in / " 36 in = 1 yd
feet ft / ' 1 ft = 12 in
yards yd 1 yd = 3 ft
miles mi 1 mi = 1760 yds / 5280 ft

Metric Units

Name Symbol Example
picometers pm 1 m = 1,000,000,000,000 pm
nanometers nm 1 m = 1,000,000,000 nm
micrometers μm 1 m = 1,000,000 μm
millimeters mm 1 m = 1,000 mm
centimeters cm 1 m = 100cm
decimeters dm 1 m = 10 dm
meters m Base Size
decameters dam or dkm 1 dam = 10 m
hectometers hm 1 hm = 100 m
kilometers km 1 km = 1,000 m
megameters Mm 1 Mm = 1,000,000 m
gigameters Gm 1 Gm = 1,000,000,000 m