| 668 mm * | 0.0393700787 in | = 26.2992125984 in | 
| 1 mm | 
| Måleenhed | Længde | 
|---|---|
| Nanometer | 668000000.0 nm | 
| Mikrometer | 668000.0 µm | 
| Nillimeter | 668.0 mm | 
| Centimeter | 66.8 cm | 
| Tomme | 26.2992125984 in | 
| Fod | 2.1916010499 ft | 
| Yard | 0.7305336833 yd | 
| Meter | 0.668 m | 
| Kilometer | 0.000668 km | 
| Nil | 0.000415076 mi | 
| Sømil | 0.0003606911 nmi | 
