| 638 cm * | 0.032808399 ft | = 20.9317585302 ft | 
| 1 cm | 
| Måleenhed | Længde | 
|---|---|
| Nanometer | 6380000000.0 nm | 
| Mikrometer | 6380000.0 µm | 
| Nillimeter | 6380.0 mm | 
| Centimeter | 638.0 cm | 
| Tomme | 251.181102363 in | 
| Fod | 20.9317585302 ft | 
| Yard | 6.9772528434 yd | 
| Meter | 6.38 m | 
| Kilometer | 0.00638 km | 
| Nil | 0.0039643482 mi | 
| Sømil | 0.0034449244 nmi | 
