1in = 25.4mm
18mm x 1in/25.4mm = 0.71in (rounded)
50 millemeters exactly.
Millemeters
6.9
1000
0.006561 feet
If the perimeter is already measured in inches, there is nothing to convert. There are 18 inches in a perimeter of 18 inches.
None, millimetres is a measure of length.
How many inches make a size 18?
18 miles = 1,140,480 inches
18 inches = 457 millimetres.
65 millimeters = 0.000065 kilometers
2.5 decimeters=250 millimeters