| 20.9 mm * | 0.1 cm | = 2.09 cm | 
| 1 mm | 
| Units of measurement | Length | 
|---|---|
| Nanometre | 20900000.0 nm | 
| Micrometre | 20900.0 µm | 
| Millimetre | 20.9 mm | 
| Centimetre | 2.09 cm | 
| Inch | 0.8228346457 in | 
| Foot | 0.0685695538 ft | 
| Yard | 0.0228565179 yd | 
| Metre | 0.0209 m | 
| Kilometre | 2.09e-05 km | 
| Mile | 1.29867e-05 mi | 
| Nautical mile | 1.12851e-05 nmi | 
