millimeters (mm)

millimeters x 0.03937 = inches

centimeters (cm)

centimeters x 10 = millimeters
centimeters x 0.3937 = inches

meters (m)

meters x 1000 = millimeters
meters x 100 = centimeters
meters x 3.281 = feet
meters per second x 3.281 = feet per second
square meters x 10.76 = square feet
square meters x 1.196 = square yards
square meters x 0.0002471 = square acres
cubic meters x 35.31 = cubic feet
cubic meters x 1.308 = cubic yards
cubic meters x 0.0008107 = acre-feet
cubic meters per second x 35.31 = cubic feet per second
cubic meters per second x 15,850.00 = gallons per minute

kilometers (km)

kilometers x 1000 = meters
kilometers x 0.6214 = miles
square kilometers x 0.3861 = square miles
cubic kilometers x 0.2399 = cubic miles

inches (in)

inches x 25.4 = millimeters
inches x 2.54 = centimeters
square inch x 6.4516 = square centimeters

feet (ft)

feet x 12 = inches
feet x 0.3048 = meters
square feet x 0.09294 = square meters
cubic feet x 0.02832 = cubic meters
acre-foot x 1233 = cubic meters

yard (yd)

yard x 3 = feet
yard x 0.9144 = meters

miles (mi)

miles x 5280 = feet
miles x 1609.3 = meters
miles x 1.609 = kilometers
square miles x 2.590 = square kilometers
cubic miles x 4.168 = cubic kilometers

acre-foot (acre-ft)

acre-ft x 1233 = cubic meters

microradian

microradian x 0.02 = second of arc