The current Renault 21 is 4,527 mm long, 1,726 mm wide and 1,409 mm tall, on a 2,617 mm wheelbase. It has grown 6 cm longer since the 1986 21.
| Years | Length | Width | Height | Wheelbase | Boot capacity | Turning circle |
|---|---|---|---|---|---|---|
| 1986–1990 | 4,464 | 1,715 | 1,414 | 2,622 | 490 | 10.5 |
| 1989–1994Current | 4,527 | 1,726 | 1,409 | 2,617 | 483 | 10.7 |
Exterior figures are manufacturer specifications for the 21, averaged per generation across its variants and shown for the most common body style. Generations with the same size are merged. Boot capacity is the seats-up figure where the manufacturer quotes one.