| 638 mm * | 0.0393700787 in | = 25.1181102362 in | 
| 1 mm | 
| Unidad de medida | Longitud | 
|---|---|
| Nanómetro | 638000000.0 nm | 
| Micrómetro | 638000.0 µm | 
| Milímetro | 638.0 mm | 
| Centímetro | 63.8 cm | 
| Pulgada | 25.1181102362 in | 
| Pie | 2.093175853 ft | 
| Yarda | 0.6977252843 yd | 
| Metro | 0.638 m | 
| Kilómetro | 0.000638 km | 
| Milla | 0.0003964348 mi | 
| Milla náutica | 0.0003444924 nmi | 
