| 668 cm * | 0.032808399 ft | = 21.9160104987 ft | 
| 1 cm | 
| Natuurkundige eenheid | Lengte | 
|---|---|
| Nanometer | 6680000000.0 nm | 
| Micrometer | 6680000.0 µm | 
| Millimeter | 6680.0 mm | 
| Centimeter | 668.0 cm | 
| Inch | 262.992125984 in | 
| Voet | 21.9160104987 ft | 
| Yard | 7.3053368329 yd | 
| Meter | 6.68 m | 
| Kilometer | 0.00668 km | 
| Mijl | 0.0041507596 mi | 
| Zeemijl | 0.0036069114 nmi | 
