| 646 cm * | 0.3937007874 in | = 254.330708661 in | 
| 1 cm | 
| Måleenhed | Længder | 
|---|---|
| Nanometer | 6460000000.0 nm | 
| Mikrometer | 6460000.0 µm | 
| Nillimeter | 6460.0 mm | 
| Centimeter | 646.0 cm | 
| Tomme | 254.330708661 in | 
| Fod | 21.1942257218 ft | 
| Yard | 7.0647419073 yd | 
| Meter | 6.46 m | 
| Kilometer | 0.00646 km | 
| Nil | 0.0040140579 mi | 
| Sømil | 0.003488121 nmi | 
