In standard film camera reference which is commonly used, a 50 mm lens equals a neutral value, or 1x magnification, so a 12x lens would be 600 mm.
1000 mm equals one meter
6.3 centimeters equals 63 mm.
15 mm
457.2 mm.
63 mm
6,800 mm
84 mm ;-)
1 km equals 100,000 mm
47 mm equals 4.7 cm
It equals 35 mm.
93 mm
150 mm