| 21 cm * | 0.01 m | = 0.21 m | 
| 1 cm | 
| Måleenhed | Længde | 
|---|---|
| Nanometer | 210000000.0 nm | 
| Mikrometer | 210000.0 µm | 
| Nillimeter | 210.0 mm | 
| Centimeter | 21.0 cm | 
| Tomme | 8.2677165354 in | 
| Fod | 0.688976378 ft | 
| Yard | 0.2296587927 yd | 
| Meter | 0.21 m | 
| Kilometer | 0.00021 km | 
| Nil | 0.000130488 mi | 
| Sømil | 0.0001133909 nmi | 
