| 491 mm * | 0.1 cm | = 49.1 cm | 
| 1 mm | 
| Units of measurement | Length | 
|---|---|
| Nanometre | 491000000.0 nm | 
| Micrometre | 491000.0 µm | 
| Millimetre | 491.0 mm | 
| Centimetre | 49.1 cm | 
| Inch | 19.3307086614 in | 
| Foot | 1.6108923885 ft | 
| Yard | 0.5369641295 yd | 
| Metre | 0.491 m | 
| Kilometre | 0.000491 km | 
| Mile | 0.0003050933 mi | 
| Nautical mile | 0.0002651188 nmi | 
