| 251 km * | 0.6213711922 mi | = 155.964169252 mi | 
| 1 km | 
| Natuurkundige eenheid | Lengtes | 
|---|---|
| Nanometer | 2.51e+14 nm | 
| Micrometer | 2.51e+11 µm | 
| Millimeter | 251000000.0 mm | 
| Centimeter | 25100000.0 cm | 
| Inch | 9881889.76378 in | 
| Voet | 823490.813648 ft | 
| Yard | 274496.937883 yd | 
| Meter | 251000.0 m | 
| Kilometer | 251.0 km | 
| Mijl | 155.964169252 mi | 
| Zeemijl | 135.529157667 nmi | 
